The main problem trying to use OT scriptures on the GT is that Christ revealed that the length of the GT was going to be shorter than originally intended so that's going to greatly affect prophecies written before this change was decided.
Mat 24:21 For then shall be great tribulation, such as was not since the beginning of the world to this time, no, nor ever shall be.
Mat 24:22 And except those days should be shortened, there should no flesh be saved: but for the elect's sake
those days shall be shortened.
There is no 7 year tribulation anymore. We all know there is a 42 month or 3.5 year tribulation in Rev 13. We also know in the gospels Christ spoke of the time of the tribulation being shortened, Matthew 24:22. Since we have a current prophecy of 3.5 years then we know it was originally longer (likely 7 years) and later shortened.
So, we won't have a 7 year trib but will have a 3.5 year long tribulation. This begins with the first beast, continues with the second beast and ends when Christ arrives at the second coming.
To shorten something means it was a certain length of time, then it was shortened to a shorter amount of time.
Mar_13:20 And except that the Lord had shortened those days, no flesh should be saved: but for the elect's sake, whom he hath chosen,
he hath shortened the days. (the original time will be shorter to benefit the elect)
No one would survive the original length of the trib so for the sake of the elect, God will shorten the trib so they can survive. This is why Paul declares some Christians will be alive and remain unto the coming of Christ.They would not have survived had the trib been it's original length.
Here we see that Jesus says the Great Tribulation was shortened. That means OT prophecy had a longer Great Tribulation than the actual Great Tribulation shall be. That is an example of a change God made to OT prophecy. In Daniel we have a 7 year trib but in Revelation we have a 3.5 year trib. God literally cut the trib in half. Going by OT prophecy alone you would have the wrong length.