Hello András
The purpose of this particular lesson is to show how certificates function. Rene could have used IKEv2 as well, but that would not make a difference as far as the certificate mechanisms go. One of the two had to be chosen, and he chose IKEv1. Also, if you look at the list of lessons in this unit, the lessons before this one cover IKEv1 only, IKEv2 is covered in subsequent lessons, so if you’re following the lessons sequentially, at this point IKEv2 has not yet been covered.
Attempting to perform this lab using IKEv2 is a good opportunity to get some lab experience in there as well…
I hope this has been helpful!
Laz