At a cursory glance, historical opinion does seem to have turned more definitely toward saying that his father is Alan Wallace.
"William Wallace was a member of the lesser nobility, but little is definitely known of his family history or even his parentage. Blind Harry's late-15th-century poem gives his father as Sir Malcolm of Elderslie; however William's own seal, found on a letter sent to the Hanse city of Lübeck in 1297,[4] gives his father's name as Alan Wallace.[5][6] This Alan Wallace may be the same as the one listed in the 1296 Ragman Rolls as a crown tenant in Ayrshire, but there is no additional confirmation.[7] Blind Harry's assertion that William was the son of Sir Malcolm of Elderslie has given rise to a tradition that William's birthplace was at Elderslie in Renfrewshire, and this is still the view of some historians,[8] including the historical William Wallace Society itself.[9] However, William's seal has given rise to a counter claim of Ellerslie in Ayrshire. There is no contemporary evidence linking him with either location, although both areas had connections with the wider Wallace family.[10] Records show early members of the family as holding estates at Riccarton, Tarbolton, and Auchincruive in Kyle, and Stenton in East Lothian.[11] They were vassals of James Stewart, 5th High Steward of Scotland as their lands fell within his territory. Wallace's brothers Malcolm and John are known from other sources.[12]"https://en.wikipedia.org/wiki/William_Wallace
Malcolm Wallace appears in the Ragman Rolls of 1296 paying allegiance to Edward I of England, however later he was one of the few Scottish nobles who refused to submit to Edward and as a result he and his son, Andrew, were executed.[5] According to some sources Malcolm was the father of the Scottish patriot William Wallace,[5] however the seal of William Wallace, rediscovered in 1999, identifies him as the son of Alan Wallace of Ayrshire, who also appears in the Ragman Roll of 1296 as "crown tenant of Ayrshire". Dr. Fiona Watson in "A Report into Sir William Wallace's connections with Ayrshire", published in March 1999, reassesses the early life of William Wallace and concludes, "Sir William Wallace was a younger son of Alan Wallace, a crown tenant in Ayrshire".https://en.wikipedia.org/wiki/Clan_Wallace
