The 2-5 am UL was there for sure in terms and conditions in the morning/yesterday. It is removed which probably means it is not valid anymore. So, their whole plans have changed too I suppose. In the December announcement, the 2-5 am UL was there too.
Overall I suppose it would force users to get an extra Jio connection for the extra night data. I was thinking of reducing a SIM and probably not taking the SIM for my newly purchased JioFI but it might be a good idea to keep the extra SIM in the case 2-5 am is not valid anymore. That would definitely reduce the flexibility of usage and so, keeping an extra Jio SIM on the Prime offer might be a good idea especially for BSNL broadband users like me. I used to keep Youtube or other data consuming work normally late night to save the data for daytime. But that would not be possible if night UL is removed. It would instead be good to take an extra SIM on Prime for safety.