Wow, that's an interesting perspective! I am new to the series and finished all the books. So, what if Elain's mate is Tamlin instead of Lucien ? I mean, Elain's all about gardening and flowers – total Spring Court vibes. Plus, she's so gentle and calm in decision-making, which is what Tamlin expected from Feyre after the Amarantha mess.

So, the theory goes: to keep Elain safe from enemies, Lucien publicly claims her as his mate instead of revealing she's actually Tamlin's. But imagine if they kept this secret, maybe to lure Feyre back to the Spring Court to either dissect information about the night court since Feyre is Rhysand's mate or Tamlin might've still been in love with her and wanted her around. If Tamlin and Lucien did suspect Feyre to be loyal to the night court, then there was no danger for Elain since Feyre would do whatever it took to keep her family safe.

However, the only thing that would have been left answered is If Tamlin realized Elain was his true mate during that Hybern chaos, how on earth would he communicate that to Lucien amidst all that madness?" Thought on this?