The GBA version did have Ethers though. They could bring back the charge system, but keep Ethers. And this version of the game is based on the GBA version, both in terms of the non-character sprite work and translation.
I'm not saying for definite either way, but simply not having an MP pool is not enough to suggest the bonus content isn't in. And as these are based on the GBA versions, they'd have to be actively removing the content. They've most likely brought back spell charges to make a version of the game a little truer to the original.
That said, the fact that they've not shown the GBA jobs for FFV is really worrying.
I don't agree that this game is based on the GBA version at all. The enemy sprites and additional cutscenes were all derived from the WSC/PS1 versions, so the GBA version is mainly defined by its mechanical differences. One of the most significant ones being MP. Plus there's a reason why they've been comparing footage of the remaster to the original version and not the GBA one.
My understanding of the purpose of these remasters is to update the originals with graphics adapted to suit modern screens while still trying to respect each game's distinct visual identity, but with the core game otherwise changed as little as possible. They're
remasters, not remakes. The name inherently implies they aren't doing anything that would wildly change the game. It's why spell charges are back, why all the new party member sprites are obviously based on the originals, and why Garland's palette was changed to more closely resemble his original look.
It's not totally clear just how closely they'll stick to the original gameplay at the moment, but I'm hoping they'll do a bit of QoL stuff and just leave all the (non-catastrophic) bugs and quirks and such intact. For example, Intelligence doesn't affect spells in the NES/FC/WSC/PS1 versions of FFI at all. And I think they should keep it that way here, because FFI with functional Intelligence is a very different game from the one people have been playing for 35 years, and would require significant rebalancing to work right. I don't really trust them to do that very well at all, and mages are still fine even with busted Int anyway.
(Also I thought all the GBA bonus content for these games pretty well sucked, so missing it does not worry me at all even though FFV is my favorite game.)