Bret Weinstein's doctoral thesis Evolutionary Trade-Offs: Emergent Constraints and Their Adaptive Consequences [1] describes the hypothesis. Telomere length limits the number of times a cell can replicate so longer telomeres hold the potential for longer life. The trade-off is that long telomeres also allow pre-cancerous tumors to grow much larger and increase the probability of a cancer promoting mutation occurring in younger animals.

[1] https://deepblue.lib.umich.edu/bitstream/handle/2027.42/6367...