I have seen a lot of channels that have way below 100k that have the verification mark. I think that page only applies to people that are directly partnered with youtube instead of a network but I may be wrong.
You will however need a large user base in order to be considered. Some channels with lower have been verified as in the past there wasn't a limit imposed by YouTube, also network staff members can be verified under this limit.
We can not disclose the exact numbers as per YouTube's instructions.