Neither of that explains the Matthew 16: 27, 28 passages.
They may have seen him, but they didn’t see him with God and all the angels. Nor did they see him with God and all the angels judging every man according to his deeds. Also “Before you taste death”, I’m pretty sure that implies some who he was speaking to would see those things happen before they died. I’m pretty certain that the Bible has never claimed that happened. But it claims that it WILL happen.
The passage is pretty specific and can’t be written off as referring to the spirit of the Kingdom. Even if it did it still doesn’t explain that He said they would see it happen.
1.) Some of the people he was talking to were taken to Heaven or elsewhere before they died.
or
2.) The passage is wrong.
or
3.) It’s misquoted or mistranslated.
Mat 16:24 Then Jesus said to His disciples....
Mat 16:28 Assuredly, I say to you, there are some standing here who shall not taste death till they see the Son of Man coming in His kingdom."
Who is standing there? Who is he talking to? His disciples. What is going to happen. They are going to "see" the son of man coming in his kingdom".
What happens next?
Mat 17:1 Now after six days Jesus took Peter, James, and John his brother, led them up on a high mountain by themselves;
He takes some disciples (some who are standing there) up a mountain.
Mat 17:2 and He was transfigured before them. His face shone like the sun, and His clothes became as white as the light.
Jesus appears to them IN A VISION (we'll look at that later) in the form he'll be in the kingdom of heaven...in the future.
Mat 17:3 And behold, Moses and Elijah appeared to them, talking with Him.
Moses and Elijah, in this FUTURE vision, are seen.
Mat 17:8 When they had lifted up their eyes, they saw no one but Jesus only.
Mat 17:9 Now as they came down from the mountain, Jesus commanded them, saying, "Tell the vision to no one until the Son of Man is risen from the dead."
So what happened? Jesus said SOME of his disciples wouldn't have to die to see Jesus coming into his kingdom. Right after that SOME of his disciples saw in a vision Jesus coming into the kingdom in a vision. Jesus told the truth. The scripture is true.