The flaw here is that not everyone will automatically become level 350 if the changes are reverted.
Yes, there will be some higher levels, but not everyone on the battlefield will have put in that time.
I think the bigger issue here, which I've noticed after playing around with a lot of different exp stages is that players lose motivation to level if exp drops below 2x. The argument there is that they "might as well play rl tibia", and this holds especially true now that there are double exp preview servers.
So now you have all of these level chasers transferring back to shadowcores because the grind is too severe. Of course you don't want all high levels running around, but it's honestly more interesting to have some than none.
Moreover, just because this is a hardcore pvp server doesn't mean that pvp is the only thing that should happen here. You want a bigger variety of players to fuel the community and keep things more interesting.
Regardless of what happens, I wish lunarforce luck. There's a serious and saddening lack of hardcore pvp servers online.