No. Merely attending the SOTU, or being someone's guest, or talking with someone, does not imply "tacit endorsement" of their agenda.
It does something different and equally pernicious. There is real impact in lending your image and accrued credibility and reputation: your social capital. The associative mind associates; semantics are an afterthought. Providing for the association is a act with moral consequences, intended or unwitting. Nye should know better.
He's not 'lending' anything to anyone, except in the reaching imagination of those obsessed with wholly-symbolic rituals of association, distancing, and shunning.
If this appearance causes some to claim Nye supports Trump's agenda – they'll quickly be refuted with all Nye's writings and performances otherwise.
If this controversy wins Nye extra media appearances, he'll there again clearly articulate his own true views for anyone who might have been confused by the childlike, pre-modern, quasi-religious doctrine that "near contaminates near with idea cooties".