A few thoughts....
1. If all goes well, it should be doable, but that is a not at all certain these days. You may well have a flight delay, variable timing on luggage, airport monorail, traffic on i-4, and I don't know how you plan to get from MCO to WDW. If you are taking a shuttle bus, that also adds time.
If necessary, you can cancel an ADR up to 2 hours , but it is also not that hard to get an ADR ate Steakhouse 71. Instead of making one now, looking for availability when you land is also an option. Mobile order is also an option.
We've had mixed experiences at Steakhouse 71. Sometimes our food has been outstanding, sometimes our food was not that great. I do suggest looking at both lunch and dinner menu ahead of time.