No, those are different chips entirely. RP1 is an entirely new chip that serves as a southbridge on Raspberry Pi 5. The original Raspberry Pi had a BCM2835 SoC. Raspberry Pi 5 has a BCM2712 SoC.
No RTC means your time is incorrect until something sets it. usually NTP, assuming the device connects to the internet right away. if it doesn't connect to the internet right away, then you just get a wrong time. it means that for any device that ever reboots, there's some amount of logging that has untrustworthy timestamps.
A battery-powered RTC means that any logs from the device aren't inherently untrustworthy.
