A few years ago, a big portion of the team that made the original Banjo-Kazooie at Rare, left the company in order to start Playtonic. The newly-formed studio made a spiritual sequel to that game called Yooka-Laylee, but fans haven't stopped hoping that they'd do a new Banjo-Kazooie game in collaboration with Microsoft.
And today they've sparked hope on Twitter because without any obvious reason or warning, someone wrote: "Kazooie is always pregnant."
Exactly what they are hinting at is, of course, unknown. However, the studio is well aware of the fact that fans will make something of this, so let's keep our fingers crossed that we're not getting our hopes up for no reason.
It's not the first time that fans have speculated that Playtonic may be working on the Rare-owned franchise. The studio had to issue a statement last November where they denied that the team was working on the Banjo-Kazooie IP, but perhaps something has changed in the meantime?