Having the new mode be the only option will force a great majority of your experienced playerbase out the window, I don't know how this information isn't common knowledge considering most, if not all mods and experienced players I know love and use legacy. I understand the want to have conformed servers but this seems so blind to the fact that your most valued players and community contributors use legacy. The new U.I just simply isn't anything in comparison and it's devastating that this new U.I is touted to be better than Legacy. You'll be saying goodbye to a lot of income from recurring customers that loved Legacy just so you can have a phone playerbase which is overall less invested into the game. To me the only favour the newer U.I has is that it *looks* fancy, but it is unmistakably and patently less friendly and useable for bigger maps like your 100 and 500 map and overall less accurate and concise compared to Legacy.
This game had so many players come back for legacy, and this decision is a kick to the face for those who have stuck with the game for years.