Here is a little bit of history (as taken from our research and placed on the
I-795 Florida Interstate Guide page) that will hopefully answer some questions:
Back in August 1986, 4.6 miles SR 9B, along with 25.1 miles of SR 9A (Eastern Beltway) were approved by FHWA as future interstate additions. As part of the agreement for the approval, a condition was set that these future freeways be built by an August 2011 deadline (a span of 25 years). As we know, SR 9A was constructed in phases during those 25 years. In September 2008, FDOT followed up with FHWA on the approval of I-295 along SR 9A and the designation of I-795 for the part of SR 9B between I-95 and I-295. I-795/SR 9B was even referenced in the March 2009 AASHTO application for I-295 along the Eastern Beltway. In October 2010, FHWA sent FDOT a letter again granting approval for I-295, per the 1986 agreement. Since the first segment of SR 9B didn't open until September 2013, it obviously didn't meet the original 2011 deadline of the 1986 agreement/approval, hence why it didn't initially get signed once completed.
For some reason, FDOT District 2 still has not formally submitted a new application for the I-795 designation. This was the latest response I received from an email sent April 20, 2020: "There are currently no developments to share at this time. I recommend following up spring of 2021." I even used my work email address (I work for FDOT District 7) and got a vague response. So, I will send another email in late March to see if I get a better answer. Luckily I have a different contact versus last year, so I will be using that person instead...