Scripture defines its own terms. Israel and only the people of Jacob/Israel are called God’s sheep.
1 Kings 22:17a “And he said, I saw all Israel scattered upon the hills, as sheep that have not a shepherd”.
Christ said,
John 10:27-29 “My sheep hear my voice, and I know them, and they follow me: And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand. My Father, which gave them me, is greater than all; and no man is able to pluck them out of my Father’s hand.”
There is no maybe someday. God’s people, His sheep, have been following Christ for almost 2000 years. They have been fulfilling every prophecy that scripture says they would. They are the same people who were called Israel in the Old Testament.
Daniel 2:44 a-b “And in the days of these kings shall the God of heaven set up a kingdom, which shall never be destroyed: and the kingdom shall not be left to other people”.
The modern day Jews are not Israel.