I'm installing windows 10 right now and even though it's not required to activate it, I'd rather do it until I can.
I've googled quite a bit about it and there's no complaints, but I'd like an additional confirmation by the piracy community here.
I appreciate any opinion
As long as you are using official Microsoft install media downloaded from Microsoft (or verify the hash to ensure what you downloaded matches the official Microsoft isos) then you should be fine.
MAS is just a PowerShell script you run after install. It's open source, and PowerShell scripts aren't compiled, so you can examine it yourself to see what it's doing. It tricks Microsoft servers into issuing your hardware an official "free upgrade" license key. The one I'm familiar with as reliable is MASgrave.
That's not an 100% guarantee that it couldn't be doing anything shady, but it would be incredibly hard for it to hide anything if it was.
TIL about this. My son will be pleased for his gaming rig he's upgrading his MOBO on in a few days.