> 1. Re-licesing the whole project is absolutely a thing.
Again, it's really not. Seriously. I don't like the idea of asking someone else to waste their time over a simple disagreement, however you're publicly providing incorrect advice and it's harmful. Thus, please point me to something, anything with some legal bearing that mentions relicensing.
What you mean is "sublicense". They're free to sublicense.
Why are they free to do this? Because the Apache 2.0 specifically grants this right. That's it. There's no implied right otherwise.
Relicensing presumably means (again, not a thing with any legal meaning) to repeat the process somehow. They can't, they don't have that right, it was never granted to them by the contributors.
Projects do change their license. This is achieved by explicit consent of all contributors. This is frequently impossible (or at least impractical) for open source projects unless the project has a Contributor License Agreement where the IP itself (and all corresponding rights) is assigned, thus permitting the project owners a different license than what they're granting end-users.
Note: Different jurisdictions interpret assigning rights differently. Many jurisdictions state that it's not possible, and the best you can do is grant a license that's effectively similar whilst simultaneously agreeing not to utilise the IP yourself in any way inconsistent with that license.
If you read my original comment, I've explicitly pointed out they can also apply the AGPL. What I've said is they can't remove the Apache 2.0. Which they have!
People need to be able to see that those contributions were made under the Apache 2.0 license, because the best Minio can do is offer those contributions with those same terms. As mentioned above, because the Apache 2.0 allows it, they can sublicense (introduce further restrictions) i.e. simultaneously apply the AGPLv3. However, they cannot ignore the terms of the Apache 2.0.
This is relevant because the Apache 2.0 contains restrictions that simply are not present in the AGPLv3. One such restriction is to not remove the Apache 2.0 license - so Minio aren't off to a great start.
There are other restrictions too, most prominently 4b.
Why am I harping on about 4b? Because quite frankly it's an incredibly stupid clause. However, like it or not, it is a clause and a condition of the Apache 2.0 license. In my eyes, it's such a stupid clause that people should outright stop using the Apache 2.0. However, seems as people tend to not read the license, or just ignore it, then sadly I can't see that happening.