Can a bad PCM eat coils?

In the last 3 years or so have been going through a coil every 6 months or so.
Then earlier this year the PCM just died, key on, no fuel pump no nothing. No coms on the obd1 port either. No one home.

Replaced the PCM start and runs well. Been 6 months or so coil has not died.
Looks to me like it was the PCM on the way out killing the coils.
Is this possible/ common?.

Usually what causes coils to fail is heat. The heat comes from different places. If you have a high voltage short or a service voltage short it can overheat the coil. Sometimes ambient temperatures degrade them over time, the engine compartment is a hostile environment.

Using the right coil is important. Old points type coils aren't going to last long in an electronic system, the coil or the driver in the regulator is going to fail. Some coils are designed to work with a three wire setup, full power during start and lower voltage for normal run. The OEM coil is usually best, then you know the coil is matched to your system. Aftermarket coils can be iffy, more spark isn't necessarily better. The system is only going to handle so much current, then something is going to fail. Voltage X Amperage equals Watts, Watts equals heat. Too much heat melts coils and damages electronics.

I had a newer coil that died, the problem was from a damaged alternator. The engine ran for a while until the coil burned out.

Replaced both the alternator and coil.

My parents' Dodge Ram van had the same issue with the same generation of PCM. The coils kept burning out until the PCM was replaced.

I don't know, you indicate an obd1 pcm.

OBD2 PCM has a coil field driver. I carry a spare PCM in case one fails.

My problem with the coil burning out was with the cracked / broken alternator.

The coil gets constant power (post Renix) as long as the ASD relay is closed. The PCM grounds the coil in pulses. If the electronic switch in the PCM sticks closed for some reason (faulty circuit) or a short in the wiring, the coil can over heat, constant power and ground, instead of a pulse. Just an educated guess, but it seems possible this could happen. It is doubtful they would engineer the coil to withstand constant power running to ground, they try to save material and money wherever possible.

Most times when a coil fails the internal windings in the coil overheat and melt some of the insulation and the high voltage archs inside the windings. I've seen the windings melt through the internal insulation, arch and eventually melt right through the outside of the coil. Usually old age and engine heat degrades the insulation, but overheating from whatever source can also start them on the road to self destruction.

Since they did away with the oil bath (cylinder) type of coil in favor of the high temp epoxy encased insulation type (usually square), the failure rate has gone way down. The epoxy encased coils sometimes fail, but it is relatively rare in my experience.