Redis is great as an off-the shelf component, but it's not exactly rocket science to re-implement for a big corporation. So redis doesn't really have any leverage in my opinion.
Then their cloud-specific solutions are the up-sell (and lock-in).
Which is why Microsoft's new drop-in replacement works with all those things. It could gain traction - who knows.
I don't think so. The only thing they need to let their customers know is that they offer a memory cache service that is compatible with this or that interface. Whether it's Redis, memcache, Garnet, or whatever it might be, it matters nothing at all. All they need to do is ensure clients can consume their service, and that is it.
This whole thing sounds like a desperate cash grab that fails to argue any point on why it's in anyone's best interests to spend small fortunes on nothing at all.
I suspect in the long run, Amazon will eventually "pay" the licensing fee for customers that demand "Redis". But they will push everyone else towards their in-house fork of Redis that they brand MemoryDB or whatever. You will pay more for the Redis licensed version and AWS will steer you away from it, but it will be there if you are adamant.
This is already happening with Aurora, which has Postgres and Mysql compatible versions. If your company is big enough for special pricing, then you know they want you on Aurora. The pricing discounts for Aurora are insane (50%+) compared to what you might get on a traditional Postgres of equivalent size (20%). They will probably do this with MemoryDB and Redis eventually. Redis is available if you really need it. But this other thing that they maintain is discountable to half the cost of the other one and it becomes a pretty obvious choice.