Reason+ subscribers will access Reason 12 on September 1st 2021. From that date perpetual licenses and upgrades will also be available for purchase.

Can you still buy reason?

Yes, you can still buy Reason a la carte.

That's true of Reason itself, upgrades, and Rack Extensions and instruments and effects included here.

Will there be a reason 12 suite?

They've said that there won't be a R12 Suite. The options are Reason+ subscription to always be up to date and have all the REs they release, or R12 standard perpetual license.