Wise to move from SuSE SLES, IMHO! Back when M$ and Novell signed that agreement to make SLES more compatible with Wonders servers/networks they accomplished that in typical fashion ... made SuSE more proprietary than Linuxes'. Greater cooperation with the open source community held promise, but the Samba folks still reverse engineer what they provide. But I digress ...
So there's a question in your post?
Are you asking if it's wise to use a higher version of PHP than required to 'future proof' the yet to be installed Moodle?
Study up on the use of yum. One can install and remove and upgrade as well as 'downgrade'. Sometimes yum can be tricky. Whatever third party repo you use, I'd advise disabling it so that an operating system security update (yum -y update) doesn't also pull in a higher version of PHP or MySQL/MariaDB that you might not want just yet.
One can install the 'latest/greatest' as long as the required extensions to PHP are there and compat with Moodle code. One could also install a version of PHP slightly higher than the required version as 'semi-future proofed' but ... all things march forward so don't look at this as install it (whatever that is) once and forget it for a long time.
Consider installing Apache using something other than 'mod' ... have read that will allow multiple versions of PHP on same server - although from the numbers you're provided, that's probably not required NOR gives any advantage.
MariaDB is supposed to be a 'drop in' replacement for MySQL.
So???????
'spirit of sharing', Ken