We can't say for sure that the current feedback loops will be identical to those that did or did not exist in the past. Differences in the initial state could result in different outcomes.

For example was there as much methane trapped in the arctics during the last time CO2 was high?

Does the rate of the increase of CO2 and temperature have an effect? Because it's currently getting hotter far faster (absurdly so) than any other period we have records for.