Hebrews 12:26 says, "Yet once more I shake not the earth only, but also heaven." This comes from Haggai 2:6 and refers to God removing an old covenant system so something new can remain.
In Deuteronomy 32:1 and Isaiah 1:2, heaven and earth are used as witnesses against Israel. This shows the language is often covenantal, not literal stars and dirt.
Hebrews 12:27 explains the shaking: "the removing of those things that are shaken, as of things that are made, that those things which cannot be shaken may remain." This means the old covenant order is removed so Christ's kingdom remains forever.
From this perspective the first shaking is seen at Mount Sinai when God established the covenant with Israel. The final shaking is the removal of that covenant system fulfilled in Christ. Jesus and the apostles use this same language to describe the transition from the old covenant age to the new covenant kingdom. What looks like cosmic collapse language in the prophets is often covenant collapse language describing nations and systems being judged. Therefore Hebrews 12 is not about literal stars or the physical planet being destroyed but about God removing an old religious order so that the kingdom of Christ cannot be shaken and will remain forever. It is a shift in covenants. Old world ends new begins in Christ. Glory remains sure.
Jesus said in Matthew 5:17-18, "I am not come to destroy, but to fulfil… till heaven and earth pass, one jot or one tittle shall in no wise pass from the law." In this view, "fulfil" means completing everything the Law and Prophets pointed to, not keeping the Mosaic system forever.
Hebrews 8:13 explains, "In that he saith, A new covenant, he hath made the first old. Now that which decayeth and waxeth old is ready to vanish away." This shows the Old Covenant was already passing in the first century, even before its final removal.
Together with Hebrews 12, the idea is a transition: the Law is fulfilled in Christ, the Old Covenant becomes obsolete, and the New Covenant kingdom remains unshakable and eternal.
In summary, Hebrews 12:26 is about God shaking the old covenant order to establish the new covenant kingdom in Christ. It is not about literal cosmic destruction but about a shift in religious systems. The old is removed so the new can remain forever.