The crash reports at https://crash-stats.mozilla.org are a separate opt in bit of telemetry which is a dialog that is shown when Firefox crashes. You can opt into automatically sending them by setting browser.crashReports.unsubmittedCheck.autoSubmit2 to true. It can be true if you opted into a dialog about submitting unsubmitted crash reports.

https://probes.telemetry.mozilla.org/?search=crash shows automatic telemetry probes. The main bit of data in that set is FX_CONTENT_CRASH_* and you can see the back and forth from the data steward and the engineer adding the probe. https://bugzilla.mozilla.org/show_bug.cgi?id=1269961#c8