I do not see anything in the parable about the 10 virgins that says that the entire world will be aware of Christ's return.
Jesus says to be watching. Why would we need to be watching if everyone would see the return of Christ?
Matthew 25:13 Watch therefore, for ye know neither the day nor the hour wherein the Son of man cometh.
Nowhere in the NT do I see any verses that say that the entire world will be aware of Christ's return.
The parable had one dichotomy: those that were prepared, and those that weren't. The masters return was announced to all of them, all 10 virgins, the prepared and unprepared, heard the announcement and were all cognizant f the fact that their master had arrived. The only question was who had conducted themselves in a manner that was acceptable towards their masters expectations.
The implication, as far as the Master's clandestine appearance is concerned, is that all the parties in question knew of his arrival - he was neither discreet nor deceptive about his return.
The entire world will see Christ's return.
Acts 1:11
After He had instructed His Apostles, Jesus ascended into heaven. While the Apostles looked up into the heavens, two angels stood beside them and said, “Ye men of Galilee, why stand ye gazing up into heaven? this same Jesus, which is taken up from you into heaven, shall so come in like manner as ye have seen him go” .
Matthew 24:30
30 Then the sign of the Son of Man will appear in heaven, and then all the tribes of the earth will mourn, and they will see ‘the Son of Man coming on the clouds of heaven’ with power and great glory.
Mark 13:24-28
24 “But in those days, after that suffering,
the sun will be darkened,
and the moon will not give its light,
25 and the stars will be falling from heaven,
and the powers in the heavens will be shaken.
26 Then they will see ‘the Son of Man coming in clouds’ with great power and glory. 27 Then he will send out the angels, and gather his elect from the four winds, from the ends of the earth to the ends of heaven.
28 “From the fig tree learn its lesson: as soon as its branch becomes tender and puts forth its leaves, you know that summer is near. 29 So also, when you see these things taking place, you know that he[a] is near, at the very gates.