Reading Garret (1913) it becomes painfully obvious where the phantom parents Thomas Beals and Sarah (Edge) Beals come from, at least in my opinion:
"... Sarah Beales was born May 29, 1713, and was the daughter of John and Sarah (Bowater) Beals. This later John Beales being tthe son of John and Mary (Clayton) Beales (sometimes spelled Beals-Bales). Sarah Bowater was the daughter of Thomas and Sarah Bowater nee Edge, who came from England...
Compare the profiles of John Beals and Sarah Bowater paying attention to the parents given names and the mother's maiden name.
Thomas Beals - Thomas Bowater
Sarah (Edge) Beals - Sarah (Edge) Bowater
John Beals Sr. [Beals-61]
Sarah Bowater Beals Underwood [Bowater-12]
And consider further, Sarah Bowater's first husband is John Beals Jr. son of John Sr.
It looks like someone, when writing their tree, added the parents of John Jr.'s wife to John Sr. by accident, transposing the Beals and Bowater names. It looks like it could be an easy mistake, especially when looking at Sarah Bowater's profile, she is Sarah Bowater Beals and her children all have the surname beals.
Once the tree is created on Ancestry or passed around as a Gedcom, other novice genealogists will go looking for any Thomas Beals, (born ~ 30 years before John Sr.) who has a wife named Sarah and then they copy dates and birth locations. It gets copied again and again and taken as gospel.
The similarities are uncanny and it is more likely than not that this originates as a transcription error.