As we know, these deals are widespread across Europe...not just the Peel Airports group!
Furthermore, as has already been commented, generally both sides now involve lawyers to the nth degree to ensure they fully understand what they are getting themselves into - I cannot believe that this doesn't also include a consideration for any possible anti-competitive behaviour.
I would be extremely surprised if it wasn't, in fact, the case that the LPL-EZY deal has no wording whatsoever to the fact that they must limit their operations at MAN or elsewhere in the North-West as this would clearly be deemed anti-competitive. After all, the two biggest players at LPL, easyJet and Ryanair, now both have reasonably substantial operations also at Manchester....so I don't really see where any sort of anti-competitive hint comes into play here?!
It is very likely the case that any agreement includes waivers or discounts off standard fees and charges on the basis that the operating carriers achieve certain volumes or growth rates. In other words a positive spin on carrier growth at the airport in question rather than a negative against any other nearby airport facility.
What is perhaps more interesting, is that whilst Peel have been happy to fight the fight against BMIbaby regarding Teesside, one assumes that a similar deal to that discussed here will be in place with Ryanair. Given that Ryanair have cut back substantially on routes from all Peel Airports (whole aircraft out of LPL, and the historically year-round MME-DUB and DSA-DUB daily routes), Peel have kept very quiet about this.
One wonders whether a compromise has been reached with Ryanair or whether it is simply the case that Peel are 'over a barrel' in that they are afraid to contest the Ryanair culls on the basis that they cannot afford to lose more traffic.