It seems that this is related to system time. You can see that restoring time from the RTC failed during boot:
[ 1.910078] rtc-ds1307 1-0068: oscillator failed, set time!
[ 1.920631] rtc-ds1307 1-0068: rtc core: registered m41t0 as rtc0
When the RTC was not able to keep system time, the system resets to some older date (date at build time). However, the journal on disk has a newer timestamp which makes systemd-journald refusing to load the journal, leading to the messages you are seeing:
[ 5.464335] systemd-journald[215]: Received request to flush runtime journal from PID 1
[ 5.493267] systemd-journald[215]: File /var/log/journal/2253ac6e062c467ca716d4ce5371db38/system.journal corrupted or uncleanly shut down, renaming and replacing.
This behavior has been introduced with systemd v232 (see journal: refuse opening journal files from the future for writing), and our 2.7 BSP series used systemd v230. That is why you only see it since our 2.8 BSP release which uses systemd v234.
In this case, the message is not really concerning. Systemd creates a new journal file and should continue to log as usual into a new file.