Not surprised to hear this going obsolete. IC manufacturers need volume to make money, and if these aren't being bought in volume anymore, they're gonna use their fab lines to make stuff that makes them money. Plus I gotta think the *602 and *612 were being made on smaller wafers and larger litho processes, which also are being obsoleted and many ICs just plain aren't getting re-scaled for the larger wafers/smaller litho.
I've had to re-PPAP several automotive sensors in the past few years just because the IC manufacturer did decide to re-tool the chip for their larger wafer line. But quite a few went permanently out of production.
This trend has been killing off great hobbyist RF BJT's for years (think the 2N5109, 2N3866, and many others...)