I think it's an overall good decision. Hell, with the way things were in Arcade, NeoMaxes might as well not have existed and nothing would have changed, and I hate when most mechanics go to waste (unless they're inherently flawed or stupid in the first place).
Agreed.
As a whole, I love the change. One thing to remember about Neomaxes, as well, is that they help the character gain a tool that's unlike their others, often. For examples, Duo gets a command Grab, Takuma gets a supreme Anti-Air, and Mai gets a blazing fast full-screen punish. Naked HD into Neomax might actually be worth it in many situations, once people are used to making it a new option in their gameplay. Before, in arcade, the HD bar was always saved as a sacrifice, and meters were blown instead. Now, you can blow HD and land a strong EXDM-style move (the NM), to save on meter burn, yet still do strong, 1-move damage. So now rather than burning the 3 meters you got from round 1, leaving you without your EX Reversal, but full HD, you can choose to Burn 2 meters and the HD bar, and still have that 1 meter to save for that game-changing EX move.
I think it'll have a nice effect on mid-game strategies. It might even change some team viability, if people really get into it. Imagine someone going HD and using their fully-invincible Neomax, VS a "not 100%" blockstring, like Maxima's cancels into Vapor Cannon? That's an option that never would have existed with 2 meters + an HD bar before.
I also think it'll lower the use of certain long combos, and make people more efficient. Rather than watching a 50 hit combo with loads of places to mess up and fail, you can now see 20 hits, then a NM.
Things like Joe Higashi being able to possible full screen punish fireballs with an EX DM -> NM now, with 4 DM bars and full drive, could make the game even more interesting, and open up new strats.