UPDATE:
After heavy testing, GPO would not delete printers not installed with a GPO so delete printers was not working on our case. Also printers were coming back because for some users they were installed as per computer and using commands below I remove them by computer first and any remaining by user.
Solution: Using PDQ Deploy and all below are command prompt steps that can run from PDQ.
Uninstall network printers per machine for old server using command (Run as deploy user(interactive): %WINDIR%\system32\Printui.exe /gd /q /n"\OLDPrintserver\Printer1"
Uninstall network printers per machine for new server using command: (Run as deploy user (interactive):%WINDIR%\system32\Printui.exe /gd /q /n"\NewPrintserver\Printer1"
Uninstall network printers per user using command (Run as logged on user):wmic printer where "Local='FALSE'" delete
Install new network printers per machine (this works better in our case, run as Deploy user (interactive) %WINDIR%\system32\Printui.exe /ga /q /n"\newprintserver\Printer1"
STOP / Start Spooler with 60 second pause so printers show up
Set Default PrinterRUNDLL32 PRINTUI.DLL,PrintUIEntry /q /y /n "\newprintserver\printer1"