That is a very good question!
Yes and no. Turns out that this is an ill-defined problem - you can’t actually exactly determine which species are differentially abundant (see gneiss tutorial).
Underneath the hood, ANCOM computes all pairwise log ratios, and attempts to infer which species changing based on this pairwise log ratio matrix. To do this, ANCOM assumes that few species are changing wrt to a variable. The balances in gneiss tries to determine which partitions of microbes can explain a variable. Because these are very different methods for answering fundamentally different questions, there are definitely scenarios where these methods give different results.