Here are the statistics on published authors found in the ISFDB. Due to the increase in self-published e-books, and the inability to easily determine the readership of those ebooks, these statistics are limited to novels that have an ISBN.

No. of Novels with ISBNs	# ISFDB Authors in Class	ISFDB Authors without Wikipedia Articles	Author Article Success Rate
100 and above	91	11	87.91%
90-99	28	5	82.14%
80-89	34	7	79.41%
70-79	52	11	78.85%
60-69	61	17	72.13%
50-59	106	27	74.53%
40-49	140	43	69.29%
30-39	284	98	65.49%
20-29	736	341	53.67%
10-19	2012	1129	43.89%
1-9	32423	26617	17.91%

It's clear from these number that publishing fewer than 20 novels does not in itself make one notable enough for a Wikipedia article. Publishing 20 or more novels makes the probability possible, but not guaranteed.

Authors with 20 Novels and an SFE Entry

The following authors have at least 20 novels with ISBNs, have an entry in The Encyclopedia of Science Fiction, and have no Wikipedia entry. There are over 1500 SF authors in this category, and only 14 of those do not have Wikipedia articles, giving an overall success rate for this category of 99.28%.

Author	Notabilty	Awards	Reviews	Add Article	Notes
David Dvorkin	Level 2	0	13	DONE (3/24/22)	23 Novels. Good candidate.
Mel Gilden	Level 2	0	13	DONE (3/25/22)	22 Novels. Good candidate. Subsequent article issues: Notability, reliable sources.
Brian N. Ball	Level 2	0	13	DONE (3/30/22)	27 Novels. Good candidate.
Edward Willett	Level 2	6	5	DONE (4/2/22)	21 Novels. 2 Aurora wins, 4 Aurora nominations. 5 reviews. Good candidate.
Guy Haley	Level 2	1	10	DONE (3/5/22)	43 Novels. Good candidate.
Fay Sampson	Level 2	0	9	DONE (4/3/22)	20 Novels. No awards. 9 reviews. Good candidate.
Mike Sirota	Level 2	0	6	DONE (3/5/22)	38 Novels. Good candidate. Article insta-killed without vote (or feedback) and moved to "draft space" by User:Modussiccandi on 6/3. This is exactly 90 days after the article was created, which is the max limit for moving articles to draft space according to the incubation guidelines.
Les Martin	Level 2	1	5	DONE (3/23/22)	24 Novels. This author previously had an article, which was deleted in 2017 due to lack of notability. I think we have more objective data to support notability at this time. Good candidate. Marked for Speedy Deletion by User:Onel5969 on 9/15/22, "because the page appears to be a repost of material that was previously deleted", which is not the case as the new article was created without reference to the deleted version. This was voted against by User:Espresso Addict, and the article was not deleted.
P. M. Griffin	Level 2	0	5	DONE (3/21/22).	24 Novels. Good candidate. Article insta-killed without vote (or feedback) and moved to "draft space" by User:Scope_creep on 5/26. Moved out of draft space by User:Espresso Addict, who also added additional reviews.
Pamela F. Service	Level 2	0	5	DONE (3/22/22)	24 Novels. Good candidate.
Robert Lory	Level 2	0	4	DONE (3/20/22)	26 Novels. Good candidate.
Nicholas Sansbury Smith	Level 2	2	0	DONE (3/26/22)	63 Novels. Good candidate. Article insta-killed without vote (or feedback) and moved to "draft space" by User:hitroMilanese on 4/25. Submitted for review by myself on 9/18/22. Article was rejected as it "needs more independent sources not primary".
David Annandale	Level 2	2	0	DONE (3/7/22)	31 Novels and over 100 works of short fiction. Good candidate. Subsequent article issues: Needs citations, relies on primary sources.
Mack Maloney	Level 2	0	2	DONE (3/20/22)	25 Novels. Good candidate. Added article. Subsequent article issues: written like a resume. (??)
Ben Counter	Level 2	0	1	DONE (3/10/22)	30 Novels. Good candidate. Added article.
Linda Joy Singleton	Level 2	0	0	DONE (3/21/22)	23 Novels. Good candidate. Added article.
Craig DiLouie	Level 2	2	3	Maybe	20 Novels. 2 award nominations. 3 reviews. Depends on whether more reviews can be found online, aside from the 3 known to the ISFDB.
Daniel Walther	Level 2	6	34	Skip	23 Novels. French author with extensive bibliography in French, but only two English translations, so very limited English exposure. Author has a French Wikipedia article, and passed in 2018, so while certainly notable, an English-language article seems unnecessary.
Christian Léourier	Level 2	8	18	Skip	21 Novels. French author with extensive bibliography in French, with no English translations. Has a French Wikipedia article. Notable, but not of interest for an English-language article.
P. J. Hérault	Level 2	0	12	Skip	29 Novels. These are all French novels, with few English translations. The author has a French Wikipedia entry, so no need for an English article.
Hiroshi Yamamoto	Level 2	5	1	Skip	32 Novels. These are all Japanese novels, with only two English translations. The author has a Japanese Wikipedia entry, and with no English presence, there no need for an English article. The current link is a disambiguation page.
C. L. Werner	Level 2	0	4	Skip	36 Novels. Biographical information is extremely sparse, so will save this for later.
Peter Cawdron	Level 2	0	3	Skip	21 Novels. No awards. 3 reviews.
Michelle Rowen	Level 2	2	0	Skip	21 Novels. 2 Goodreads award nominations. No reviews. The current link is a redirect to the author's Falling Kingdoms series
Sarah Fine	Level 2	1	1	Skip	21 Novels. 1 award nomination. 1 review.
Jill Williamson	Level 2	0	0	Skip	22 Novels. No awards, and no reviews. Would need other evidence to move forward with an article.
Susan Squires	Level 2	0	0	Skip	20 Novels. No awards. No reviews.
Sergio Funaro	Level 2	0	0	Skip	20 Novels. No awards. No reviews.