Seeing as the Xbox One isn't hacked/modded yet, I'd assume they've toned it down a bit for that system... but for the 360, I know they actively monitor and check for modded gamerscore. I've never modded gamerscore, but the key to it from what I gather it to do it in moderation... if you sign offline and sign back in 5 minutes later with 100,000 more gamerscore, it's going to set off red flags everywhere. They take that kinda thing pretty seriously in all honesty.
Yeah i modded mine back on 2012 on the 360 and it's still not been reset must go grinded like 40k gamerscore
On Xbox one legit kinda hope i don't get reset I should be safe as it's been like 6 years or
If it's been 6 years, you're probably in the clear as long as you don't do anything to bring attention to your account. If you get suspended for a rule violation, and Microsoft does some digging on your account, you could get banned... not likely, just be careful.