I don’t get it. If you’re using one of those things at all (and most successful java organizations moved away from them long before docker, IME) it’s because you’re memory-constrained, but in that case the overhead of docker would be something you want to avoid.
This article didn’t make much sense to me either. If you can afford to do a rolling upgrade of docker images I’m not sure why that is, all of a sudden, less resource-expensive to you than doing a rolling restart application servers. In other words, as far as I can tell docker is replacing people learning how to use their package manager, not changing how software could or should have been deployed.