Welcome back, Gary.
The short answer is, almost certainly, yes.
The long answer: Nothing much has changed regarding the way in which everything works in providing the data to emonCMS, so your Tx still sends its radio data packet to the RFM69Pi, and the RFM69Pi still sends the serial data via the header pins to the RPi. At the same time, the emonGLCD picks up the radio transmission and displays it.
I have an emonTx V2, V3.2 & V3.4 and GLCD, all working on the old 868 MHz radio and they all work with the latest emonCMS.
The only change is likely to be in the data format that emonCMS expects from your emonTx - the modern sketch sends rather more and so that might mean that you need, before you upgrade emonCMS, to take a copy of your emonhub.conf so that you can replace the new node definition for your emonTx’s NodeID with your old one.
Recovering your historic data is likely to be a problem - but my knowledge in that area is all but non-existent, so somebody else will need to advise you on that.
In any case, I’d advise starting with a new SD card.