Number 2 could certainly paraphrase #1, Guest, but I can't say that I've ever heard #2 spoken or seen it written. Number 1 is pretty much a frozen formula.
Have you/Did you google(d) it?
It's not a "frozen formula", albeit. This does not really explain it. This is a fixed expression. Also, it's worth pointing out that this is a subjunctive form. However, as such subjunctive forms are very few, it's easier to simply call it a fixed expression unless a student demands a complete explanation of the phrase "come what may", and other phrases such as "be that as it may", and "suffice it to say".