While He was in human form, I think He was limited. The "things he knew" were about the people He knew personally at that time, or who figured during His earthly sojourn.
He was "surprised" at the Centurion's faith. He asked "Who touched me?" to find out who the woman with the issue was.
He didn't talk about Joe Blog from the year 2021, or people outside His personal acquaintance, other than in general terms eg. "... many will come from the east and west ...", "... but few there be who find it...".
So, no, I don't think he knew everyone who would be saved.
He may have been divine, but He was also human with all the limitations that implied - he got hungry, thirsty and tired.
Nor do I think He knew, and still doesn't know the date of His return. God may be a unified Trinity, but they're still three persons, and I think God the Father is the only one who knows when the Second Coming will eventuate, even now.
For whatever reason, He's playing that one very close to His chest. Something to do with "... if the strong man had known when the thief was coming...".