I don't see any issue, as long as you consider the time until the system crashes or stops for any other reason rather than the time until the system stops specifically due to a crash.

And note that the Lindy effect is about the expected value (mean). The statement "probably run another T hours without incident" could be interpreted as relating to the median, which is actually a little less than the mean. So the statement should either be "the expected value of the number of hours until the system stops is T", or "the probability of the system running for at least another T hours is a little less than 50%".