He could meet his past allies in a different context. For instance, he might encounter Kakyoin or Polnareff when they were just starting their journey. Maybe he could also run into Dio at a time when Dio was still plotting his rise to power, which would create a very tense situation.
Kira's downfall in the Death Note manga occurs when his identity is exposed and he's cornered by the forces opposing him. It's a combination of smart detective work and unforeseen circumstances. His fate is both tragic and inevitable given his actions.
Honestly, we just don't know. It could potentially continue if there's enough interest and the right circumstances, but as of now, there's no definite answer.
It's been a bit challenging. The continuation without Miura has faced mixed reactions from fans, but some still hold out hope for a decent continuation.