This has been my experience in the past with a heavily snapshot covered codebase. Class names can change, the structure of your HTML can change, the underlying CSS can even change and the end result is still the same because you were just refactoring. At a large enough scale it can be painful to have hundreds of snapshots break for a simple change - especially when you add required code review by others into the mix.

Currently figuring out a strategy for introducing testing into an already large codebase and being very cautious of snapshot tests because of this. Experimenting with visual regression testing but early indicators suggest it could get very expensive if we're not careful about what is covered.