I've wanted a normal/ghost type for years. Hopefully it doesn't end up with some bizarre stat spread or a terrible movepool.
Generally speaking, Regionals don't wildly change the stat spread. And for the exceptions, its usually because they had a different (usually better) plan in mind entirely and distinguished the Pokemon as such.
Zoroarks stats are 60 - 105 - 60 - 120 - 60 - 105. So assuming they don't try to reinvent the wheel, we'll probably still have a good sweeper.
Now, the most dramatic single stat changes between a pokemon and it's regionals are:
Darmanitan (Zen Mode) - Attack from 30 to 160
Galarian Zen Mode, rather than trying to change to a defensive form mid-fight, instead becomes an even more aggressive and fragile attack form. This works much better with Darmanitan's build overall, and doesn't require managing two seperate forms. It's undeniably an improvement.
Persian/Perserker - Speed from 115 to 50.
Perserker is basically an entirely new and unrelated Pokemon, and it's stats are wildly different as a result.
G-Meowth - Speed from 90 to 40
As it's evolving to an entirely different pokemon, it's stats undergo similarly drastic shifts to match.
Cofagrigus/Runerigus - Swap attack and special attack, 95 and 50 each.
Again, they're presented as entirely different Pokemon. Not to mention, this doesn't wildly affect their competitive viability, as they just change which attack stat they prefer.
No one else has a stat swing bigger than 30 points. And I'd argue in most cases that the stat swing plays in the Pokemon's favour in the extreme cases.
Not to mention, some don't have their stats change at all.
If I had to take a guess at what the stat change will be, it'll be just swapping the attack and special stats. Perfectly viable, if a bit squishy, but a good type combo will help a lot with that.