They could have just left their costumes standing, as the gleaming pop-house god reservists that they are (except while temporarily leaving reservist status) and silently move on to doing other projects, as they've always done.
Really wonder what triggered the announcement. My guess is either heavy disagreement, perhaps about retiring the bots and continuing as Thomas and Guy-Manuel, or the total opposite, becoming aware that they were likely fading out of those roles forever and deciding that the bots deserve to go with a bang.