A couple of small things
As noted in the linked article, this is a working copy of the map made by Pauline Baynes; this map was first published in 1970. So the things of interest are Tolkien's notes to her, which I'll attempt to summarize.
The new information is:
Corsairs had red sails with black star or eye
Numenorean (Gondor) ships black and silver
Rhun and Mordor had many wild kine and horses
We knew that there were kine in Rhûn; Denethor says as much:
Vorondil father of Mardil hunted the wild kine of Araw in the far fields of Rhûn.
Return of the King Book V Chapter 1: "Minas Tirith"
But we didn't know about the wild horses, or about any animal life in Mordor
Minas Tirith is about at latitude of Ravenna (but is 900 miles east of Hobbiton, more near Belgrade)
Bottom of the map (400 miles) is about at latitude of Jerusalem. Umbar & city of Corsairs - about that of Cypres.
Though these perhaps could have been determined from knowing the latitude of Hobbiton, as far as I know these findings were not previously published
Elven ships could be grey
And things we already knew:
- The place names were all known at least from when the map was published in 1970
- The Westron translation of Eryn Vorn ("dark wood" or Blackwood) was known; it was published at least in A Reader's Companion
That Hobbiton is about at the latitude of Oxford was revealed by Tolkien in Letter 294:
If Hobbiton and Rivendell are taken (as intended) to be at about the latitude of Oxford, then Minas Tirith, 600 miles south, is at about the latitude of Florence.
The Letters of J.R.R. Tolkien 294: To Charlotte and Dennis Plimmer. February 1967
It has been known at least since The Letters of J.R.R. Tolkien was first published in 1981
We already knew that Elven ships were white