In and of itself it says nothing. For many people that would be a sign of kidney yin deficiency, but there are many other ways to get nightsweats than that pattern.
If you look through our nightsweats treatment options page, near the bottom where -possible- formulas are listed you will see below their name and general uses their functional category and subcategory - so for a few you see “tonify the yin”, but you also see “tonify qi”, “clear heat”, “calm the spirit”, etc. - so any of those (and more) are possibilities.
Generally you never take one symptom and use that to form any kind of conclusion - you take the entire range of everything, past and present and use that to form a working idea of how the symptoms came to be.