All 16 Bible translations that I have on my Online Bible program use the English subjunctive in Philippians 2:10. Fourteen of them use the English subjunctive “should” to translate the Greek subjunctive and the other two use the the English subjunctive “may.”
Personally I have encountered NO translation that uses the simple future “will” instead. To do so would be an incorrect translation.
Also, it’s a mistake to presume that using the subjunctive in this verse makes “every knee bowing” any less certain. As has been pointed out already, the subjunctive shows God’s purpose. God highly exalted Jesus and gave Him a name above every name SO THAT every knee will bow and every tongue confess that Jesus is their Lord.
The word “should” does NOT mean “ought to” in this verse, nor, if it is translated as “may” does it mean “might or might not.” Used in that way, the words are NOT subjunctives. Again, the subjunctive mood simply expresses God’s purpose in highly exalting Jesus.