Agree completely. If we were to sign someone of the level of Mbappe or PEA, then it'd be pretty backwards to break up a front 3 that, for once, looks genuinely exciting and capable of achieving some success. If we settle for a Lacazette then we need them even more so to raise the level.
Take the hit, we'll have money to replace them next summer regardless and I have a feeling they're both bluffing anyway, especially Mesut.