If the available tools to meet the standards are obsolete to the point of being dangerous, then how does that increase safety?
There are a lot of 172RGs and old Arrows that are 20 years past the time they should have been scraped. Remember this all came about because a relatively low time, and presumably well maintained PA-28R had a wing snap off.
CMEL pilots will still train in complex aircraft and 99% of CFIs spend virtually all their time in fixed gear airplanes (unless they are MEI).
I've heard that school of thought before...
An old boss once said - out loud in front of everybody - "the aviation business would be such a great business if we could just run it without pilots and airplanes."
If this decision really came about because a new-ish Arrow broke up in flight, this is probably amongst the most ridiculous and non-germane responses to a problem I've ever heard.
First rule of problems, when trying to solve one, don't create more!
If this decision came about due to old haggard aircraft in the fleet, that's a different story. Yet, then my answer would revert to BUY NEW AIRPLANES! (see pp 1, above).
Too many aviation businesses are milking 40-50 year old aircraft. They're like slot machines. Amortized 20 or 30 times already. Don't put a dime into them. Just let the students keep plugging them with coin.
As to your safety argument... Is it really increasing the margin of safety by having students do their training (your 99%) in busted down old chitboxes, and then having them do their checkrides (your 1%) in something else??!? So they're safer for 1% of their commercial training experience, and then don't demonstrate their proficiency in the complex aircraft... is that the benefit, or am I missing something??
Let me reiterate the first rule of problems: When you're fixing a problem, don't enact a "solution" that creates new problems. Yeah, yeah, I know... big picture, systems thinking is required. Where's the short-term profit in that? Probably out of scope.