You can use your M3 MacBook Pro with dual monitors now, just like the M3 MacBook AirOwners of M3 MacBook Pro can now enjoy the dual monitor feature after a recent software update, similar to the M3 MacBook Air.
MacBook Air gets hosed, other models hold steady in macOS 15 as Intel support fadesIntel Macs made in the mid-to-late 2010s receive fewer macOS updates compared to older models, but more support than old PowerPC Macs post-processor switch.