If you own a perpetual licence then you get to keep it when you change to subscription.
If and until the license is revoked, as is possible with many products, including the Adobe suite, which used activation every time the software was used (and yes, this includes the
nonsubscription perpetual version like CS2 or earlier). Again, all spelled out in the EULA. Adobe (and others) have the ability to prevent the perpetual software from being used IF the end user breaks the EULA. So no, you have access to the license, you don't own it or the software.