Yeah, I don't know about that. Unless something else has majorly changed, Final Quest appears to take place "only" about 60-100 years after SATS, which itself only takes place about 10-15 years (probably less) after the end of KOTBW and the Shards storyline.
(Reasoning: in KOTBW, Shuna is shown to be a little girl, while she's a young adult, probably a teen, in Shards. I'd put her in her 20s in SATS, at most. In old Final Quest promo images, Shuna is shown as elderly. It's hard to judge exactly how old she is by her physical appearance -- she could be as "young" as 65 or as old as 100, depending on whether a hard life ages humans prematurely in this world, or conversely whether being around the Palace has magically extended her life a bit.)
When Leetah and Cutter were reunited in KOTBW, he asks her to remove his wolf-blood, and initially she responds enthusiastically (something like, "I've waited so long for you to ask me to do that!"), but then in very next panel she realizes she "knows nothing of waiting" -- after all, in her personal timeline, she and Cutter have "only" been together approximately 20-25 years; whereas, she's talking to him just after he's spent over 500 years waiting to be reunited with her. So the upshot of that (I'd have to go back and read it again to be sure how it falls out) is that she almost kind of talks him out of making a hasty decision about doing that.
Given that she came to that conclusion, would 600+ year old Leetah really feel after only about 60-100 more years that she is "fed up" with waiting for Cutter to make a decision about his wolf-blood? It seems like it would be too soon for her to become "fed up" -- because really, most of the time, what is there about his having wolf-blood for her to be fed up about? Nothing, really.
Leetah has always seemed to understand that his wolf-blood is part of what makes him HIM. And they've all had the experience of watching what happened to Skywise as he adjusted to not having wolf-blood. What would it mean to the CHIEF of the wolfriders to give up some of the abilities that his wolf-blood gives to him?
The only reason Leetah has wanted to remove Cutter's wolf-blood is that she's afraid of eventually losing him to old age and a natural death. (If he gets that far!
) But that eventuality is a long way off. Although neither she nor Winnowill ever stated outright if they knew, it's possible they know in a general way what a wolfrider's natural life-span could be; and haven't we been given estimates that it could be as long as 1500-2500 years? Cutter is an extremely long way from it becoming an issue, in other words; and there is no real reason for Leetah to become impatient about it during the time-frame we seem to be talking about.
If anything, I'd think that removing Cutter's wolf-blood would increase the danger of his dying sooner. The example of Skywise showed that removing the wolf-blood removes some of the senses and abilities that the wolfriders have, which presumably makes them better at the lifestyle they lead (hunting and so on). It's impossible to imagine Cutter giving up those things that wolfriders enjoy, like hunting. But removing his wolf-blood could make him less good at them, and thus increase the odds of his dying by accident.
Otherwise, though... yeah, not sure what that cryptic hint could be referring to! But then, I was no good at trying to guess at the cryptic hint given to us about that picture ("what is Cutter missing?" ... um, his vest? New Moon? Sure, Leetah was with him, but otherwise, technically speaking, "the entire rest of the tribe" was missing from the picture... so what? Ehn, these kinds of riddles just irritate me.)