I went ahead and ordered the Four Seasons 58440 compressor since adding A/C back onto my car was on the todo list.
Sure enough it has the wrong connector. Looks like it's for an R50.
It's a single wire and there is an insert explaining why it's a single wire. The old compressors (rotary vane style) were prone to overheating and were 2 wire with the internal temperature switch on the second wire/connector and the newer compressors (piston swash style) don't require this.
Also included is a package of butt splice connectors with writing on the package indicating to use these to splice into the OEM wiring since the connectors may not match.
So, there you go! It should work fine.
I probably won't get to this for a couple more months but I plan to just go ahead and 'upgrade' my OEM compressor wiring by using a pigtail I'll cut off an R50 the next time I'm at the junk yard. I no longer have the original compressor; otherwise I'd just swap the connector over on the compressor side.