I think TLK will happen strictly with Emma and Hook when one of them is injured by a curse as a result of something that happens trying to defeat the WW.
My headcannon is that Hook will be compelled to kiss Emma again in order to save her, because he knows deep down that she loves him. However, I think too that it would be quite ironic if the kiss came about because Emma was finally forced to admit to herself that she loved Hook in order to save him, allowing those walls she built up to come down, and thus giving the TLK more gravitas.
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