How about if you try this: For each reskin, replace it with an entirely new weapon. Then we'll never need any more weapons again!
For example, Normal shard bombs work like the old shard bombs, freeze brandish becomes a freeze whip, plauge needle becomes sniper rifle, etc.etc.etc. (Note: These are just examples. I am NOT saying normal shards have to be oRSS or your Glacius will become a whip.)
The problem is that there are only 7 unique guns, 9 unique swords (counting FoV), and 6 unique bombs (8 if you're being fair). At the end of the day, I actually have a lot less choices than it seems.
You are pretty much asking OOO to make new weapons from scratch, which is what's happening now. You can't just ask them to make things up out of thin air, it takes time to come up with new models and such. And things like Glacius and the shard bombs are not reskins, they all are different even if only slightly. A reskin is something like Scissors Blades or the chef cleavers; weapons that function in the EXACT same way as another weapon, but with a different look.
Alternatively, if you mean just to change the look of all these weapons without changing functionality, then that wouldn't bring anything new to the game. It would just be a reskin, which is what everyone hates.