Hi @Arjohn Macabalo ,
Before you start sysprep you should disconnect machine from domain and remove unnecessary users profiles:
https://learn.microsoft.com/en-us/azure/virtual-desktop/set-up-golden-image
I would suggest to create image, then build new machine from image, add to domain.
Next you could assign GPO to proper OU in AD and move session hosts there.
Please look into below blueprint for AVD where you can find some useful scripts.
https://github.com/Azure/AVDBlueprint