I'm not sure today where Jet2 fits into the Lo Co spectrum. They were certainly a product of the Lo Co revolution, but with their 22kg baggage allowance and other frills perhaps they have crossed the line, in the same way that I wouldn't lump TUI in with the Lo Co.
Thats being generous isn't it? The whole point of the LoCo's is that you get the basic flight and everything else is optional, which is exactly what the flight element o(and what we know the airlines for) are based on.
I assume you're talking about the Tour Operator arms of Jet2 and TUI, with the inclusive baggage. Both are just a holiday company who use a certain airline and have the full/some of the bag cost already included.
We're not yet into the realms of Easyjet being there with their 'holidays' offering, but if theirs did come with a hold bag included, would they be classed as the same as Jet2/TUI?