If I'm not mistaken Dembele and Coutinho should be amortized fully next summer. That in combination with fans returning to games and the museum should relax things a bit. Not sure about the economical consequences of Leo leaving though.
Dembele's contract expires next summer, if he doesn't renew then yeah I'd think he would be fully amortized (it doesn't matter if he leaves for free anyways), but Coutinho's current contract is through 2023, so he wouldn't be fully amortized until 2023, unless we sell him, right?
Not very optimistic about what to expect from fans returning to the stadium. The Spanish government including governments of the autonomous regions agreed to start the league at a 40% capacity, I don't know if we will be easily filling Camp Nou with 40,000 people now with COVID, barely no foreign tourists and with Messi leaving. Same with the museum. Messi leaving definitely will hurt us financially from a sponsorship and merchandise perspective (however I don't buy the 300m figure), let's see what the impact is.