This is an odd take, seeing as the Iranians have been backing the Houthis for a while (though arguably started mostly after the Sunni gulf states intervened in the civil war) and similarly with Hamas.
Hamas' military wing is quite decentralised, to allow it to continue to function even if commanders are killed. Most Palestinians I know think the political wing leaders in Qatar etc probably weren't even aware the attack was coming, let alone the Iranians or Hezbollah. Whether this is true or not, we'll probably never know.
Those groups have their own agency with regards to what to do and their aims and not everything is some major coordinated plot from Iran. If there was a coordinated plan from Iran, Hezbollah and the Houthis would have struck at the same time as Hamas and Israel would be fighting an actual war on 2 fronts at the moment (with one enemy vastly more powerful than Hamas), rather than 1 full war on 1 front and another with small exchanges.