Injector Coil for 2009 a Subaru Outback Sport

I recently had to replace my injector coil for my 2009 Subaru OBS with about 58,000 mi on it. When I picked it up at the shop (not the dealer) the mechanic said the dealer had about 30 in stock since this is a common occurrence due to the colder temperatures experienced in Massachusetts. Is this an accurate assessment of the reason the coil cracked? Is there anything I can do to prevent it from happening again? (Particularly since it’s a dealer only part no 3rd party replacements available)

Fuel Injector, or Ignition Coil?

Please clarify.

BC.

My mistake Ignition Coil…