Ostia Antica (FTWHS Italy)
https://www.comune.fiumicino.rm.it/index.php/notizie/comunicati-stampa/item/1421-montino-ostia-antica-e-portus-patrimonio-dell-umanita-dal-comune-di-fiumicino-piena-disponibilita
It is, in fact, astonishing that the largest and best preserved Roman city, alongside Pompei, has never made it to the list. It is superior to any other Roman sites except Rome and Pompei and if it were somewhere else it would have long been submitted and inscribed. I wonder, however, what chances another Roman site stands, especially in Italy.

I totally agree with you. I had actually forgotten it is a FTWHS, it does not make sense... I am convinced there's plenty of chances for a site as brilliant as this one.

Australia, Belgium, Denmark, Finland

Workers' assembly halls

Another article on a possible future transnational candidature for workers' assembly halls:

Could workers' assembly halls soon become World Heritage sites?

As for the Danish Workers Museum and its project partners in Australia, Finland and Belgium, they will need to be patient. Although the museum plans to submit its nomination application before the end of the year, the UNESCO World Heritage Committee will only decide on the bid in 2025.

There is a mention of a bid for 2025, yet none of the possible components have been put on the Tentative List of the respective country.

In October 2021, a new "tentative site" appeared on the Danish website of the ministry of culture: Salt og Tang på Læsø (Salt and seaweed on Læsø). It's still not on the official UNESCO website section, however.

Cambodia:
https://asianews.network/two-sites-selected-for-unesco-world-natural-heritage-list/

Ireland:
https://www.clareecho.ie/decision-on-burren-holy-island-unesco-status-to-be-made-next-month/

The Architectural Work of Erich Mendelsohn

Yet another modernist architecture on the list. Similar to Le Corbusier. Looks promissing. Future serial site. Countries involved: USA, United Kingdom, Norway, Czechia, Germany, Russia, Israel and Poland.
https://www.slazag.pl/najwazniejszy-zabytek-slaskiego-modernizmu-na-liscie-swiatowego-dziedzictwa-unesco-procedura-ruszyla

Oh interesting, I am rather fond of Menelsohn, but have only really visited 2 sites.
I'm not fully convinced it would really have OUV, but it certainly appeals to me personally, and the De La Warr Pavillion is certainly worthy of being wider known.

Upper Awash (Ethiopia)
https://satenaw.com/authority-aspiring-to-get-upper-awash-basin-registered-as-world-heritage-site/

Rather than being an example of "aspiring to be on the T List" this is either a re-naming or (possibly?) a reformulation of the existing TWHS of Melka Kunture.
Note this site's history of attempted inscriptions going back to 1978 and (most recently) in 2022 as "Incomplete"! It would seem likely to get renominated soon?
I see I am one of only 2 to have recorded a visit (in 2008 in our case) - I will do a first review unless it and its photo are considered "too outdated"!!!

Ah, yes, you are right! They did try to nominate it last year, but the dossier was incomplete. It has a looooong site history, dating back to 1978.
Reviews are welcome!

https://ca.news.yahoo.com/international-bid-planned-oil-fields-154331155.html

Early Oil Sites (transnational)