As far as the size, all of the units we sold have been approximately the same size for quite a while. E.g. all the chasses varied by maybe 6-10" max between the old assemblies and the new. The new ones were larger (maybe more room for power electronics?) I don't know if there was any effort on our part to support 5G transition without replacing our antennas.
Edit: I believe we were pushing new hardware because the services wanted to utilize the high frequency band of FR2 24-56Gz [1] (what I meant by "true 5G") that our old antenna assemblies couldn't support. I assume they couldn't support it because they weren't optimized for those bands at a high enough fidelity for good data transmission.
[1] https://en.wikipedia.org/wiki/5G#Frequency_range_2_(24%E2%80...