I kind of agree with this.
I have loaded for a lot of .280AIs. With a 22", a 140 will pretty easily hit 3100+. A 150 will be above 3000. A 168 will be close to the 2900 mark. A 175 should get just a bit over 2800.
If you want to run a 120-150 in a 6.5mm with a standard BF, standard feed lips, and LA @ 3000-3200 in a 22", with available factory ammo, there are not a lot of options that will get you there that will feed reliably. 6.5-06AI would easily hit that 3000+ with a 140. But it is not factory. 6.5-280AI will get a touch more. 6.5 Sherman even more. The 6.5RPM won't get anything a 6.5-06 won't do. I have loaded for one and wasn't overwhelmed by the performance. 6.5-06 (not AI) performance. But it is a cool idea.
.270 Win is another option. Tons of factory ammo, but easy to handload for. 120-150gr bullets will be in that 3000-3200 range. Even 165, 170, 175 if you have the twist for those. You can go .270AI, and still shoot factory ammo if you want, then handload for more performance later.
6.5SAUM would easily get there, but Mag BF. Same with 6.5SS, 6.5Max, 6.5Mega, etc. You could do a bolt swap to a magnum BF. Even 6.5PRC would get close. 140s @ 2950 are doable in a 22". Might need to go with a DBM and CF mag though.