They are announcing this for 2-3 weeks straight already and every time their attacks are "imminent" (first called for this operation even before those 2-3 weeks). They are probably not sure about the success rate of their attacks or if it could make the situation even worse for them.
At this point, even if they do something, it is more likely that they will fail judging by their own hesitation even if their own delusional and hubris-filled minds. If even those arrogant idiots are this hesitant, then you can truly be sure. Therefore, I'm not very worried for Houthis.
Today or yesterday Houthis started attacking US and UK warships for the first time (only they are engaging with Houthis presently, other Western nations rejected the US, this is a big telling sign in itself as well). I think that to be honest, the US got clowned on hard by Houthis.
Meanwhile Iran also got back the oil tanker that the US previously stole from them:
