Where's the evidence for this though? So far as I'm aware, no Konami rep or producer has said as much, right?
Also you can watch the mobile gameplay on YouTube videos and it looks very similar, with shared gameplay and UI elements signalling the same basic set of features, albeit simplified for touchscreen usage (which might change if/when they add controller support).
Look:
The movement, the commands (match up is there, e.g.), the physics – it looks like a scaled down version of what we have on console. And that shouldn't be surprising; it was the whole pitch going into this, and probably a big reason behind choosing UE as well.
So what's the evidence this is somehow a different game, and that the original crossplay ambitions are now off the table?
What makes more sense to me is to take them at their word and place those ambitions in a context of them failing to deliver and so pushing back plans to do things like crossplay (alongside other things on their roadmap).
The idea was always to get cross console play setup, and to do so first before mobile crossplay. Would you conclude that because we haven't got Xbox vs PS yet, and no word of it, that actually they are different games on those platforms? Obviously you wouldn't, so why is this a consideration in concluding that the mobile game is now completely separate?