It depends actually. I have seen CBT resets for various reasons. If you do a failover to another host, if there is a sudden shutdown of the host (and then the host loses it's CBT information) or, as you state, when integration tools are updated and depending on what is in the update (so it is not every time actually) it can reset this also.
Windows server 2016 hyper-v will fix this but I'm afraid the older server solutions will always have this possibility.
You don't need to do a new full backup, as we will continue to do an incremental, however, we need to scan the VM to see what the changes are, and therefore, you will notice that the backup takes longer.
Hope it helps