Between the 17 threads on this 200 series head gasket issue, I feel nobody can say with complete confidence it is a coolant issue, especially when people like me with a mere 115k miles and a dealer receipt of my last coolant flush at 78K four years ago and light use followed all maintenance protocols. Yes, you should still do your preventative maintenance to be safe.
I fell down a rabbit hole on this (my wife thinks I am obsessing) since this happened to us recently. There are several things I have seen common in my reading of all these threads (and videos):
1) appears to more prevalent in pre 2015 years
2) lots of talk of cracked radiators (mine too was discovered), yet no overheating issues ever in my, and others, case.
3) lots of mention of valley pan gaskets leaking
Personally a coolant flush is wise,
but it would be safer to conduct the occasional coolant pressure leak test. That "may" be the key here, I don't know.