Not only is it typically not immediately vested for founders, but it's not totally uncommon for future rounds to "unvest" founders. E.g. let's say you raise yo

Not only is it typically not immediately vested for founders, but it's not totally uncommon for future rounds to "unvest" founders. E.g. let's say you raise your A after 4 years, the terms of the round might require that you unvest 2 years so that the investors have you locked in for longer, to avoid the issue discussed in the original post.