It's one of those things that's easier to spot on a re-read, definitely. On first encounter, it comes across as "Friendly Reminder: Cross-House Marriages Are Forbidden!" to clue in new readers who might not know that Piro needs a Tiassa love interest before one is introduced, and remind those who read The Phoenix Guards of Khaavren's ill-fated cross-House crush > successful intra-House marriage romantic arc.

But it's a lie! :D The real clue is that Piro, too, will end up in a cross-House relationship with a Dzurlord. (We get a later clue that Piro has eyes only for the House of Dzur when he meets Tazendra, and his brain is fried by conflicting signals of "Dad's old friend! -- Oh no she's hot.")

Love the Morrolan Pie Chart icon! :D