The Japanese era name will be changed on May 1, 2019. According to the Japanese government, they are considering preliminary announcement around the spring/summer of 2018. The glibc ja_JP locale must be updated to include the new era name for strptime/strftime support.
Is there anything preventing dev_ack here? It is clear that the information - which kanji - and which name will become the new era name have to be known. dev_ack has been set for the rhel7 and rhel8 glibc bz, and would express that we think we can fix this bz. Our partners are also asking for z-stream errata. With the dev_ack, we can approach PM and ask for chances for the z-stream fixes.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2019:0724