This is on point in many ways.
There's got to be a balance between tokens and items. With an abundance of items (as is the state currently) the server won't get as many donations as it can because the players won't have enough tokens to purchase the newer items. Putting items on rotation without having buy power on the server won't lead to good results. It'll just make the donated limited time items more expensive and close to nearly unobtainable in-game. Vice versa also applies. There's got to be liquidity and a demand for different items.
Which brings us to a more complex point, which is class balancing. This is a super complex conversation and I'm not as well informed, we'll leave this part to the more experienced and technical players. (Cookie, Mano, etc). However theoretically, if there's saturation and only a few classes are played, the server is going to stagnate after a point. Fewer sales in certain sectors of item sales (specifically Soul linker capes/weps, Stalker capes/weps, etc)
I'd suggest having a sort of rotation while monitoring the number of active tokens/classes/items, coming down to some sort of ratio. Based on the ratio if there's a lack of tokens, create a token sale in the shop until the desired ratio is reached (IRL done as *till stocks last* sort of sales). If there's a high demand for items, create an item sale (IRL this is done in a way more stable manner with new stuff being released a little bit before a major holiday/seasonal purchasing event). If certain classes are constantly played, evaluate why, evaluate what the other classes are lacking and have them updated to the necessary place. Having a steady token sink in the game for impatient players might help as well (Similar to how you can purchase the f.king set for 100 tokens in the game or the casino, or farming for seeds, etc)
This is far from everything that's needed but thanks to everyone who's posted here. I hope we continue having productive discussions such as this one.