If there going to finish power rangers.

They sould do a big reunion battle Malaore from in space ( Malabore is from Turbo movie but forgoten the name of the one from In Space but same monster) he returns bigger more power full.It calls It every ranger there is from every season. everyone from 1st season to this new season.
like a bigger better virson of wf forever red but a movie or a season.
plz say if u got a better idea of that.

Malagore was from Turbo.
Dark Specter was from in Space.

As for your idea. Not everyone can make an appearance. Trini can never ever show up again cause the actress is dead. Rocky won't show up because of the actor won't show up or even bother talking to the PR people. I don't like the idea myself. If it was just MMPR-WF sure thing, but including the garbage Rangers from NS-MF is just a waste of time and resources.

ok not every single people will be on the show ok

i bet it will be a good show a great ending if they do it right