It's common enough for there to be a
NHTSA bulletin about it. Per the bulletin "A difference in the expansion rate between the plastic water channel and steel reinforcement plates may cause stress cracks to occur at the edges of the reinforcement plates."
Nothing you can really do to prevent it. Fewer (and less severe) temperature changes make it less likely. Somewhat reasonable if you have a climate controlled garage and/or live in a place with ill defined seasons, haha. But if you live in a place that gets really cold having a climate controlled garage
could then contribute to the chances of this happening. But that wouldn't make me leave my car out in the cold.
It might be worth picking up the repair kit to have on hand, PN 5GM 898 041. I see it for as low as $0.73 right now
.
There is also sealant called out by the bulletin, PN D 172 090 A2. It's $20-30. Wouldn't be surprise if it's shelf-life limited so I would get it when needed.