Meh, I’ve never seen an uptime (SLA) guarantee that was worth anything anyway. They’re consistently toothless, publicly-offered ones anyway (can’t comment on privately-negotiated ones). I’ve written about it a few times, with a couple of specific examples:
https://hn.algolia.com/?type=comment&query=sla+chrismorgan.
But not acknowledging actual outages, yeah, that would open you up to accusations of fraud, which is probably in theory much more serious.