Usually, on cloud or VPS hosting the cPanel accounts are unlimited, but you will have to buy the cPanel/WHM license additionally for that server.
If it goes with shared hosting packages, they have some limitations, but you do not need to pay for the license additionally.
With new cPanel pricing, based on account number unlimited cPanel "unlimited" account reseller will probably stop to exists as it's 45$ for 100 account + 0.20$ for each additional accounts. So if you have 1000 accounts on your reseller/vps/cloud license for cPanel will cost you 225$/m alone.
Yes, cPanel has increased the pricing, but there is never something "unlimited". If the added domains or cPanel accounts are unlimited, there is still the limits of the server resources, which limits how much sites or applications can be hosted on that server.
I think it is not a problem because they will limit the resource on the account and I am sure users can not use unlimited cPanel account. It is just a way to attract potential customers who like unlimited features.
@agmhost You have no idea what "Cloud Hosting" means, do you? cPanel licensing depends of the license installed, not of the web host. any WHM license installed gives a number of cPanel control panel licenses. Then there are a pricing structure for each cPanel license used above 100.