None of this mentions a gap in Daniel's 70 weeks. It only assumes one is there. Still no 7 year tribulation scripture can account for.
The issue we have with Daniel_9:24-27 is that there are a number of prophecies within these prophetic verses which are, in reality, not linked in any way with the first mention of 70 weeks of years. However, because we can find 69 weeks of years mentioned in verse 25 and 1 week of years in verse 27, many have assumed a common timeline for all of the prophecies. This is not true.
The timespan for the Daniel_9:26b prophecy is defined by the start being when the prince, i.e. the Little Horn, comes with an army to bring desolations to the land and Jerusalem and the ending point of the prophecy is when the war in heaven with Satan and the other fallen wicked heavenly hosts is over in our near future.
Now, verse 27 comes into play after the war in heaven is over as it does not overlap the prophecy in verse 26b, however, there is a time gap of 1,000 years where Satan is unable to have any influence over the people of the earth because immediately he is thrown out of heaven down to the earth he is imprisoned in the Bottomless pit for 1,000 years. Now the prophecy in verse 27 is a prophecy about deception and we are told in Rev_20:7-8 that when Satan is released from heaven that he will go out to the nations of the world to deceive them.
Now the 490 years mentioned in Daniel_9:24 is continuous and is over at the end of the fourth Age of mankind/the end of the second age of Israelite's existence.
The 483 years mentioned in Daniel_9:25 start a little later after the start of the 490 years of verse 24 and ends a number of years after the start of the fifth age after Christ is born.
Embedded in prophecy, Daniel_9:26 and Revelation_12, 20, there is a gap of some 3,000 or so years between when Jerusalem is desolated and devastated and the Daniel_9:27 prophecy.
Just because people saw a pattern of two 490 year time periods, through the ability to add three time periods together, does not mean that the time period of Daniel_9:25-27 must occur within a forced and continuous time period of 490 years as many also suggest.
Whether I am right or wrong, my explanation makes some sense as to why there is such a big time span occurring between when the devastation and desolation of Jerusalem starts and the solemn seven year covenant mentioned in verse 27 begins.
Only after Satan is released from the Bottomless Pit for a little while i.e. for a period of around 20-30 years, does the Daniel_9:27 prophecy come into play and unfolds over a seven year period.
Over the second three and a half year period of the one week of years is when the false prophet encourages the people of the earth to begin worshipping the beast with the treat of death and starvation, possibly, if people will not.
After this period of time, God's wrath will increase until the end is decreed.
Shalom