remain to be seen

/R IH0 M EY1 N T UW0 B IY0 S IY0 N/
verb
  1. 1

    To have not yet happened; to be as yet unknown.

    โ€œIt remains to be seen whether he will win the election.โ€

Source: https://en.wiktionary.org/wiki/remain%20to%20be%20seen