Intermittent "Gear !" Symbol after ABS Replacement

[BimmerBarlow]

I keep my '02 325 convertible in Florida near our vacation home. It can sit idle for as much as a month or two without driving it. I recently had the ABS controller replaced with a rebuilt unit.The replacement went well and the mechanic said it would cost an additional $150 to reprogram the computer "because it didn't recognize the VIN". This mismatch results in yellow brake and ABS warning lights on the dash. Since I have no intention of selling this car I could care less if the lights are on as long as the both the brakes and ABS are working properly (they are working, I've tested in wet parking lots to confirm).
Recently, when I first drive the car after sitting I have been getting the gear ! warning and limp mode within a mile of driving the car. After turning the car off it seems to reset and I can drive for a couple weeks without ever seeing the gear ! warning again. On my last trip the gear ! warning came up unexpectedly on startup so something is definitely changing (getting worse) in the tranny. I have experienced zero issues with the transmission while driving other than limp mode. No noise or slipping. It has about 106K on the odo and the transmission has never been serviced. I got it scanned and the code was "DTC (1) - ESG (electronic Transmission Control), transmission switch."
Are the ABS controller replacement and the transmission warning lights related?
I will probably schedule a transmission service with the dealership when I return. Any advice on first/next steps would be greatly appreciated.

[328 Power 04]

It definitely needs to be programmed, and the rest of the car systems depend on the ABS working and communicating properly. It had little to do with VIN, and a lot more with getting all the car settings in and calibrations in.

If you have a Windows laptop and a BMW K+DCAN cable it can be done remotely over wifi. There's no reason to ignore that programming and then chase other problems that could be related.