SP was not trying to add any content whatsoever, all what we were getting just more and more monsters.
If there's not gonna be an option to ascend your Legendary monster to Mythical rarity so why they still sell Forsaken Monsters? They announce that Legendary monsters are useless and pushing Forsaken sales at same time. Only yesterday they told us about "future events with Forsaken Monsters" and selling them as "unique opportunity". It sickens me badly but if it is gonna be soft reset I'm actually glad bc I needed this final push to quit the game.
I agree with previous posts that bringing new rarity won't help because SP doesn't see other ways to develop the game, make it interesting and profitable at same time, but spawning new monsters at ridiculous speed.
They could add Guild Castle and lots of things where players gladly invested their time or money for building Castle and getting some benefits similar to premium pass perks: speed of hatching/extracting, increasing slots in Vault and %chances of successful breeding etc
Instead of completely abandoning L rarity and only getting new Mythical monsters we should be getting ways to ascend old legendaries to M rarity by getting Mythical rarity cells or completing certain quests, meeting certain conditions. Ascending would enable new sets of skills/traits apart of stats bonuses. Or even enabling sets of certain equipment giving developers another way of making money by introducing new content.
Another thing to make players to use more kinds of monsters could be introducing some kind of synergy bonuses when we use certain group of monsters (like friends or family related) which we could somehow increase...
There lots of ways to make current game work, I can think of tens just sitting now on my lunch break at work. But SP wants just draw another monster and sell it. They couldn't even solve problem with overpopulation of monsters for whole this time. You making 3 monsters every 2nd week now so just forget animated monsters on habitats. Noone cares anymore who walks on each island, make just view of islands and certain element habitats, if we want to see monsters in them we could just click on habitat at and see who lives there on a manner of Vault but not as useless as in Vault but earning gold . This will give you another source for players putting some effort in unlocking places in habitats for earning gold.
So it's up to you SP either be creative and make everyone happy or be lazy and lose dedicated players.
Most of newly released monsters are very situational. They either have cool traits or some great skill but for certain set up. But you never gonna rank them up to max bc they never outshine likes of thalassa, ragnarok or max ranked pumpkin and Forsaken. So everyone just sits on pile of elemental cells and waiting for some good Elite but Forsaken/Warmaster