Perhaps it was a little sarcastic! Let's re-examine the quote and assume that you're only talking about the situation in the second row.
James Ryan is a superb talent. I honestly can't think about one aspect of his game that's subpar; he leads well, hits like a train, carries strongly, supports play, has great hands, adds ballast to scrums and is good out of touch. However he had one total start as a pro player and 100 minutes on the field for his province. He's coming off a month out through injury. Playing a monstrous pack from a team topping the Top 14.
The man he replaced has started the season brilliantly for Leinster. He demolishes rucks and shows great workrate. He's incredibly disruptive to opposition rucks. He's been capped almost 40 times and has nearly 100 Super Rugby appearances. He's match fit.
To say James Ryan coming in ahead of Scott Fardy improved Leinster is plainly wrong. Ryan will become a phenomenal player and I'm delighted to see him get lots of game time. By the end of the season, injury permitting, he'll be neck and neck with Devin Toner and Scott Fardy when it comes to selection for big games. Next week with Fardy back in contention, I'd be very surprised if Ryan isn't moved down to the bench and used as an impact sub.
If we're to examine the "Injuries probably helped" line, as pointed out the calibre of player missing can't have improved the team. You could argue that it has allowed Leinster to rotate their squad which may stand to them later in the season. You could possibly also argue that it's a great sign that 12 of the starting XV were born in 1990 or later which bodes well for the future. Against that, had anyone been asked five years ago what the current Leinster team would like like now, chances are that'd namecheck Jamie Hagan, Marty Moore, John Cooney, Ian McKinley, Ian Madigan, Eoin O'Malley, Luke Fitzgerald, Niall Morris, Andrew Conway and Brendan Macken among the mainstays of the team. Who knows what the future holds?