There is a draft of Divine Worship: The Gradual, circulating around ordinariate circles, which is a revised edition of the Burgess psalm-tone Propers arranged according to the Ordinariate Calendar & Divine Worship the Missal. It is in square notes, and edited by Burt circa 2017. The presumption is that the Chancery was looking to add this to the growing number of official ordinariate books. However, the recent publication of The Anglican Use Gradual, Second Edition, of which I do not have a copy but which I presume is the finalized version of the so-called Divine Worship: The Gradual is highly suggestive that this project was nixed by the chancery. If that is the case, I would not be too unhappy, as it seems silly to me to promulgate an official graduale of psalm-toned propers, when the most obvious choice would be to edit the Plainchant Gradual according to Divine Worship.

I do know that the US ordinariate hymnal in its later stages of evolution, so perhaps the project of the graduale was put on the backburner in order to work on the hymnal instead.

Other than the difference in notation with the St. Peter Gradual, and the welcome restoration of latin incipits (which the St. Peter left out), the draft of Divine Worship: The Gradual contains a complete set of votive masses, as well as all of the special antiphons for various feasts such as the entrance rites on Palm Sunday, various Triduum chants, the entrance right of Candlemas, Sprinkling rite antiphons, the Advent and Lent Prose, the O Antiphons for Sapientiatide, etc. I assume these made it into the Anglican Use Gradual, Second Edition as well.

I do know that the US ordinariate hymnal in its later stages of evolution, so perhaps the project of the graduale was put on the backburner in order to work on the hymnal instead.

I find it strange to publish yet another hymnal when the 1940 Hymnal used in the Episcopal Church would fill the gap with great ease.

I imagine they're trying to get away from using hymnals which are literally protestant hymnals, despite the gems they may contain. In my area, less in-the-know folks are often confused about what exactly the Ordinariate is. Using a hymnal from a prominent American protestant denomination probably doesn't help distinguish them as Catholic. I know I would feel more comfortable singing from a difinitively Catholic hymnal, and conversely I would feel strange always singing from an Episcopalian book. This is total speculation on my part though; maybe their reasons are wholly unrelated to this.

I know I would certainly be interested…

There are some weaknesses I have noticed in the 1940 other than the awkwardness of of singing from a denominational hymnal, which will hopefully be addressed by a diocesan hymnal for the ordinariate

1. There is a dearth of Marian hymns
2. The communion hymn section does not express the full riches of Catholic eucharistic theology, except for the few notable translations of office hymns such as Adoro Te, etc.
3. There are no gregorian masses in original latin

In addition, the new hymnal would include settings of the english office hymns in Divine Worship: The Office so that the office can be more easily sung.