After protest in that same thread, the PO staff seems open to undoing the reversal in code. Whether or not that will actually happen, we'll have to wait to see. Tentatively, I'd still suggest people stick with NBS for their GSC needs in things like SPL and the ongoing old-gen mashup tourney (if not because of the future possibility of losing the Glitch Drum, then for the bug in the current client where Ice-types can be frozen by Ice Beam in GSC).
As for RBY, I can kinda understand their reasoning there. They cite a (perhaps exaggerated, but I'm no dev so I really don't know) difficulty and time cost with adopting all the quirks of the carts, potential for bugginess, etc. With that, Stadium RBY now and cart RBY later is better than no RBY now and both RBYs later, imo.