No not true, in my case my .enc backup was from 9.1 was on a thumb drive and was taken from the machine I was trying to restore it to and it would not restore without sending it back to AC for the 'magic' program to allow it to be used to restore data to 9.1 build 254. Just sayin.
Also I tried reloading AC 9.1 onto that same machine which it had been on and functioning prior to the 'crash' and couldn't do it without getting a new ID number from support.
Could it be that since I had to get a 'new' ID number to even load AC 9.1 that the 'old' 9.1 enc file had an old ID number?
Can't AC 'identify the machines so that additional support and my time is not wasted getting new ID numbers, I mean Windows 10 reloaded using it's 'old' ID number no tech time required.