That has been kicking around in the deal discussions since the end of May, yeah. Nothing much about this MoU seems to have really changed since then:

https://www.timesofisrael.com/liveblog_entry/emerging-us-ira...

https://www.yahoo.com/news/politics/articles/iran-could-rece...

Two diplomats briefed on the latest draft called it “an international ‘investment fund,’ which the United States would help facilitate in the event of a final deal,” and plans for which would be discussed during the initial 60-day negotiations period that the memorandum would kick off, the report says.

It appears to concern the authorisation of a sort of Marshall Plan inward investment fund that may end up holding that sort of amount of cash that the US effectively agrees to facilitate and allow.

But I guess a key thing is that it involves is the USA agreeing not to seize it. It would also implicitly allow businesses to do the reconstruction work without being sanctioned.