Depending on what the deleted functionality is, vulnerabilities in that functionality may not affect you anyway even if you're using NTP Classic. If you're not

Depending on what the deleted functionality is, vulnerabilities in that functionality may not affect you anyway even if you're using NTP Classic. If you're not using that functionality to begin with, then it's hard to be affected by vulnerabilities in it. I say "depending on what it is" because of course you can have functionality that, even though you don't care about it, you still can't actually turn off (e.g. a protocol server that implements commands you don't care about, but can't disable). It's not clear to me offhand whether the NTP Classic functionality that NTPsec deleted is the type that doesn't affect you if you don't use it, or if it's the type that can't be disabled.