I'm glad others are here and posting about this still!
I still play GW2 pretty much everyday, although on PC I've not been playing many multiplayer matches these days thanks to lack of anti-cheat, and the lack of any kind of response or update is frustrating to say the least. The GW games are great games, flawed in some ways for sure, but still some of the most fun I've had in my 4 decades or so of playing video games. PvZ in general needs more attention than just new plants to buy in PvZ2 for real money.
Look at the Reddit, at YouTube, and elsewhere, the fanbase for these is still significant, and considering the nature of the IP, it wouldn't be hard to get new fans or attract the kids of older fans to play, even if you just do some needed work to GW2 and let people get their achievements, that would go a long way.
I'd love a sequel, as unlikely as that feels today. BfN can't be the last PvZ shooter, as while I don't hate it like some, it was certainly a letdown after the wonderful GW games. A GW3 or a GW: Regrown game, where we get all the best stuff of GW and GW2 in one cross-platform package, with the needed balance changes, improved netcode, and actual communication, anti-cheat, and other stuff like new maps, would be the best possible outcome.
The silence is the worst part. BfN has been in maintenance mode for 3 years now, and no news on a new shooter, or at least some quality of life updates for GW2 is insufficient to say the least.