It is not unsafe.
davido didn't say that: "This works but is NOT recommended, and can be unsafe", and at least to me it's obvious that this refers to what you said:
it can be unsafe if used upon strings of dubious provenience
If one is doing eval, one is usually using it on strings based on user input or dynamically generated strings, otherwise one wouldn't have to eval in the first place!
Stringy eval is one of those "only do this if you really know what you are doing" type of things, so while your clarification certainly isn't wrong, I also think warning against it is absolutely the right thing.