The following 2017 youtube video says the lightning network hubs will charge money . . .
1. Is it true
It is possible. However, users of the Lightning Network will configure their software to search for the cheapest path available. As such, competition will keep those fees low. If someone chooses to run a node with a high fee, then nobody will create a path using that node, and the node owner won't generate any revenue.
and may the banks start owning hubs?
Sure. If they want to, and if the laws in their jurisdiction allow them to. Anyone can run a hub, even you.
2. The same video later-on (6.5 minutes into the video)says the block was limited in size to create a monopoly:
That is not true. The block is limited in size to PREVENT a monopoly.