The Ethopian legend about Menelik does not fit the historical time frames for the events of the appearance of the Ark in Aksum. In all probability, Menelik was not a historical figure.
Not in any way to detract from the expectation of the imminent appearance of the Ark. Chapter 18 of Issiah forecasts the delivery of a gift which is an "ensign" from Ethopia to the Mount of Zion at a time of famine in Ethopia.
Since I do not read Daniel 9:26-27 as requiring construction of a Third Temple, I see the probable circumstances as a little different.
Daniel 9:27 says that at the time of the Abomination of Desolation event, approximately three and one-half years before the return of Jesus Christ, the sacrificial worship system will be terminated by the Prince of 9:26. Obviously, by implication, the worship system must be reinstated prior to that date since it has not been conducted since the late spring of 70 A.D.
Many believers read into this forecast, the proposition that the Temple must be rebuilt to permit the sacrifices to resume. Maybe. But we know of no reason to believe that is so--the sacrifices were conducted many years before the first temple was constructed in a tent and they could be resumed at that location at any time.
Many Jews expect the sacrifices to resume when the Messiah comes--so return of the Ark from Ethopia might well trigger the appearance of an individual of Jewish ancestry in Bethlehem who claims to be the Messiah who will confirm a treaty with Israel initiating the sacrifices.
"the sacrificial worship system will be terminated by the Prince of 9:26"
If you read Dan. Chapter 9 together to keep the context, it becomes very clear in Dan. 9:24-26 that the Prince of 9:26 is the Messiah. He came to terminate the sacrifices and that's what Jesus did. This prophecy has already been fulfilled.