You go to heaven by having total faith in the Gospel message. You have faith in Jesus when He said "I am the way, the truth, and the life". To give credence to other religions is blasphemy and deserves Hell.
As to the video, there is no doubt that many believers will come from the worlds steeped in Islam, or Hinduism, or atheism, etc.
I know this because Jesus sent His gospel out to the world ...
Acts 1:8 "But you will receive power, the Holy Spirit having come upon you, and you will be witnesses for Me, both in Jerusalem and in all Judea and Samaria, and
to the uttermost part of the earth."
So there is no question that God has other sheep ... who are not among us ...
John 10:16
I have other sheep that are not of this sheep pen. I must bring them also. They too will listen to my voice, and there shall be one flock and one shepherd.
And I have personally heard testimony of those to whom God delivered the message of salvation apart from the preaching of men ... through a dream or a vision, etc. Consider the
God-fearer Cornelius.
Also consider that the scriptures detail the the risen Christ, Himself, stormed the gates of death/Hell, and, Himself, preached to the captives, ...
1 Peter 3
18 For Christ also hath once suffered for sins, the just for the unjust, that he might bring us to God, being put to death in the flesh, but quickened by the Spirit:
19 By which also he went and preached unto the spirits in prison;
20 Which sometime were disobedient, when once the longsuffering of God waited in the days of Noah, while the ark was a preparing, wherein few, that is, eight souls were saved by water.
Finally, we know, from the scriptures, ... that God has saved many who have never heard the gospel from men. For we know that He saved ...
Enoch (who He translated)
Noah (the drunkard)
Abraham (the liar)
Sarah (who laughed at the promise of God)
Isaac (the son of his father)
Jacob (the con-man)
Joseph (the dreamer)
Moses (the murderer)
Rahab (the prostitute)
Gedeon (the God-tester)
Barak (who needed Deborah by his side)
Samson (the vow-breaker)
David (the adulterer/murderer)
Samuel (he who answered the call of God by night)
He has saved all of these ... who heard no preaching of the gospel by men, ... because
GOD met them personally in their lives ...
Bible Gateway passage: Hebrews 11 - King James Version
Certainly God has not limited His methods to the preaching of men in this age. We all know that He would not have it be that a single soul is left dependent upon the fragility of the work of men.
For God, says Peter ...
2 Peter 3:9 The Lord is not slack concerning
His promise, as some count slackness, but is longsuffering toward us,
not willing that any should perish, but that all should come to repentance.