"net time" is a deprecated command and can NOT be used to check which server a domain member is syncing with. A domain member will ignore the manually configured time server and sync using the domain hierarchy. If the time sync on your clients has been working until now, then it will continue to do so.
The only thing you should verify is that both DCs changed their method successfully.
On both DCs, run the following command:
w32tm /dumpreg /subkey:parameters
The "type" value should be NT5DS on server1, and NTP on the PDCe.