Maybe not an active approach but they let the other la fall by the way side for whatever reason (and their might be a financial reason).
There's an assumption there that Munster and Ulster have been well run provinces when they haven't been. Ulster moreso, they have been financially reckless and a lot of IRFU policies, such as the central contracting system favouring the team with most internationals, are heavily influenced by them destroying the team from the inside out, they actually have an extra source of income thrpugh UK Gov. grants and have remained the 3rd / 4th best province.
Munster totally neglected development in the 00s, they've been steadily improving and are obviously the last Irish club side to win a trophy (with the coach that pushed back most against IRFU selection policy which can't be ignored). They have been providing apprentice players and young squad players to Ireland in the most recent cycle at a far improved rate. However, there's nearly a 10 year age gap between Conor Murray and Simon Zebo and Craig Casey, I don't think they produced a 20+ cap international inbetween, that's not on the IRFU.
Leinster have essentially had back to back golden generations, it happens in sport as relatively uncompetitive as club rugby. The most recent one is at risk of being totally wasted at club level if they don't win Europe in the next two seasons and it's undeniable, and has been for a couple years now. The next gen doesn't look as dominant. It should balance out after 2-6 frustrating years for Ireland if recent 20s squads are indicative of talent.
However, criticising the IRFU is missing the failings of the Munster and Ulster branches.
Do they have the same access to the schools as Leinster? Saw some fans moaning that's part of the issue and that Leinster don't let the best lads go out for development. Which in turns a problem because the squads actually too big.
They can approach them but selling it to players is impossible. Ages 23 - 26 has been the period where some Leinster players' careers have stalled. Ryan Baird is a prime example, he's never been a starter in his career, Jamie Osborne is at risk of same currently.
@LeinsterMan (NotTigsMan) asked me what players I'd be happy to see go abroad on a deal that allows them play for Ireland and I never answered, Jamie Osborne would be top of the list for me right now, he is at a stage that he needs to be a starter and he can be at a higher level than Munster or Ulster can currently offer. Back when Munster were at a level that gave players exposure to top level club rugby both Joey Carbery and Andrew Conway moved with varyijg levels of success.