I "poked" around a little and find several problems ... but, in answer to this particular question, online trees state alleged wife as Elizabeth Thomas, Jane Luffman, Elizabeth Jane Thomas, none are sourced. The link you provided says Betty, but Betty was not a common nickname until the late 1750s, so where that one came from is also unclear. The research conducted by a family investigator in 1928 (posted on FAG as you mentioned) says no wife was ever identified for Thomas. Of course, research has changed in 90 plus years...
Still, as above, I found no records or sources naming a wife. Henrico VA records were burned/lost in 1865 courthouse fires, but I checked Virginia Archives and the State Library archival records for marriages under his name and got -zip- (no surprise). His will mentions no wife, so she died before he did.
While the duplicate profiles should be merged, I couldn't find any valid source that names his wife, first or last. Since this is a pre-1700s profile, sources are required. As there are no records of her existence or their marriage, she should probably be detached, but since most incoming people will look for her (since the connex is all over the web) perhaps a reassignment of Elizabeth Unknown and a Bio note that says there is no proof of a name/marriage due to records loss/ etc...?
I did notice an active wikitree contributor is cited at the profile bottom as having compiled notes on the family. He is one of the profile managers for the linked profile you provided. He edited the marriage data on Thomas' profile in 2017, per the changes tab. Perhaps he has additional information.
Hoped for a better outcome, but it looks like this is a wall many have tried to break down w/o success. Cheers. Kc