Well there is an established pattern.
base chip launches, MBA, 13” MBP, then the Mini with the base and Pro and MBP with Pro and Max, followed later by the Studio with the Max and Ultra, with this year the Mac Pro alongside the Studio.
expect a similar pattern with M3.
so don’t expect the Mac Pro to refresh when the M3 launches but alongside the Studio with the Ultra
but no reason to believe that the Pro won’t refresh alongside the Studio which tends to be the last part refreshed. They will just wait till the Ultra launches which is the last part to be done.
way more MBP sell then Studio so they get the demand for new MBP out with the Pro and Max and then worry about the Studio/Pro desktops.
