RHEL/CentOS and Debian/Ubuntu are all viable server OS. RHEL/CentOS are more common in US. Debian/Ubuntu are very common in Europe, etc. and with cloud instances.

I find the RHEL tooling to be more baroque and arcane than the Debian tooling, and the latter is generally nicer to read output from. Debian isn't primarily targeting UI-based use cases, and Ubuntu inherits its system tooling from them. The arguments of 'it starts automatically' are a RHEL vs Debian debate, not Ubuntu specifically, and I think they're a canard, to be honest. If you're installing a system where a brief window of localhost-only mysql server could be compromised, you're already in an usual position - you're installing a database system on a sever that other, untrusted entities are already using. If you're concerned, you could simply install your pre-seed config file before installing mysql instead of after it, as Debian doesn't overwrite altered config files.

Re: apache: at least apache on deb-based systems keeps the same name everywhere, and you don't have to remember which part of the system calls it httpd and which part calls it apache :)