I think many people might have expected an increased Ryanair presence by now - I did - so if (when) it comes it will be no great surprise. With many UK airports seeing impressive passenger growth at the moment CWL should be well positioned to step up its excellent performance of the past ten months.
Other rumours that I've heard doing the rounds, with provenance suggesting that they might be more than hopeful spotters' gossip, involve Jet2 spreading from its 'northern heartland' with CWL one of three airports that they have approached. It might even be that Jet2 is the low cost airline that the airport chairman said had approached them that very day when addressing a WAG committee a few weeks ago
I have no doubt that airports speak to airlines all the time but if these rumours have some basis there might be more to it. That said, negotiations don't always result in positive outcomes of course.