To be clear, this isn't about preload. The 'loose' tolerances is a reference to how tight the machining is on the rollers and raceways. If someone posts the p/n's for the actual spec'd bearings, you can look up both & see the numbers.
Think machined to 4 digits past the decimal instead of 6 digits past the decimal; that sort of thing.
Not implying that the numbers I gave you are trashy bearings; they're not. But the original numbers are tighter tolerance.
Charlie