No, your suspicion is not correct. The export in 32-bit float is still supported, of course! So, if you have rolled back to 9.5.30 solely due to this issue then you can safely reinstall 9.5.40 and there is no reason to be frustrated 
Now, in Cubase 9.5.40, the following six options are available for the Bit Depth parameter: 8 bit, 16 bit, 24 bit, 32 bit, 32 bit float, 64 bit float. So, just choose the 32 bit float option and Ableton Live will import and process that exported file correctly.
Best regards
Miloslav