Is there lore for Overwatch characters infinitely respawning?

There is one hero which the lore of OW does sort of support infinitely respawning -- Reaper:

Reyes resurfaced as a volatile mercenary known as "Reaper." His identity and motives remained unknown. Now a ruthless and remorseless killer, he was responsible for terrorist attacks throughout the world. He fought in many armed conflicts over the decades, showing no loyalty to any cause or organization. Survivors described him as a black shadow ghosting unscathed through the most hellish battlefields. The few bodies recovered of his victims were pale, empty husks drained of life, their cells showing signs of intense degradation. It was speculated that Reaper was a byproduct of failed genetic alteration which forced his cells to simultaneously decay and regenerate at a hyper-accelerated rate.

Those attempting to track his movements began to see a pattern in his appearances. They believed that Reaper was hunting former Overwatch agents and systematically eliminating them.

Keywords from the summary:

speculated that Reaper was a byproduct of failed genetic alteration which forced his cells to simultaneously decay and regenerate at a hyper-accelerated rate.

This, in accordance with his interactions with Mercy supports that after the bombing of OW HQ, Reaper can constantly regenerate his cells even after he decays. Some quotes after he respawns are "The grave cannot hold me back" perhaps indicating he's done this before.