Salam Br. Tayo. Thanks for waiting. Here are my two cents based on the language and how it is used in the book. And I do study the Quran carefully, very carefully, though to err is human. Thanks for your kind advice.
The Arabic words derived from “hamza bā wāw” are used for forefathers (both paternal and maternal as well as uncles, thus - ancestors), and parents (both mom and dad). For example:
[4:11]: ….And for one's PARENTS (wali-abawayhi), to each one of them is a sixth of his estate if he left children….
In the above, dual masculine noun is used for both parents, mom and dad, same in 7:27, 12:99, etc. The same dual noun is used to indicate two fathers in 12:6, in this case grandfather and grand-grandfather. Thus, context and the construct determines appropriate meanings.
In its plural form to mean both paternal and maternal forefathers - ancestors, it is used extensively. For example 13:23, 40:8, 24:31, 24:61, etc.:
[24:31]: ….. and not expose their adornment except to their husbands, their fathers (ābāihinna – BOTH MATERNAL AND PATERNAL grandfathers included), …..
[24:61]: There is not upon the blind [any] constraint nor upon the lame constraint nor upon the ill constraint nor upon yourselves when you eat from your [own] houses or the houses of your fathers (ābāikum – BOTH MATERNAL AND PATERNAL grandfathers, in fact, ancestors) or the houses of your mothers or the houses of your brothers or the houses of your sisters or the houses of your father's brothers or the houses of your father's sisters or the houses of your mother's brothers or the houses of your mother's sisters or [from houses] whose keys you possess or [from the house] of your friend. There is no blame upon you whether you eat together or separately. But when you enter houses, give greetings of peace upon each other - a greeting from Allah , blessed and good. Thus does Allah make clear to you the verses [of ordinance] that you may understand.
Thus, the correct translation of the word in 6:87 would be “ancestors” to avoid the confusion for English readers. Therefore, your conclusion is not valid. I hope this helps.