By the front office, yes. They have asked Kearns if he would try this; they have not communicated anything to Larkin. Larkin has repeatedly said he would work at other positions; all the FO has to do is let him know.
I think it's great Kearns is going to give 3B a try. Worst-case scenario is it doesn't work out, and we're back to where we were yesterday. Best-case, he could man 3B for years.
I do think that if Kearns does not play 3B this year, Freel will. I suspect they'd rather non-tender Jimenez and go find a 2B, and handle 3B from within.