Mostly of these shows never explain anything.

Power Rangers lives or dies off of MMPR which is why most seasons try to rehash it in order to be successful. Saban, Disney, and Hasbro did it in order to bring back older casual fans to watch the show again.

Would Hasbro capable to make a original Pr show with a original footage ?

Eventually maybe. But then is it still power rangers? Does hasbro create everything or still import mechs and suits and film all new? I honestly dont know.

Perhaps yes, they could make some sort of partnership with Toei in mecha design and stuff.

It won't be impossible for it to happen. Robotech and Voltron did original stuf with original footage without Macross and GoLion. Power Rangers is not much different from those two (They are Americanize adaptions of Japanese kids shows).

But they have enough budget to do such thing ?

I think the biggest obstacle is Zord scenes. I don't think US has kaiju studio, and if they go full CGI they'll ruin it.

However you can counter this by making an animated Power Rangers.

A animated seris is out of question.

I agree- if it becomes an animated series it loses alot of the charm.