[EDIT remove "roughly speaking an order of magnitude"]
No. No it is not. 787 approach speed is 145-153 knots. It does not cruise at 1400+ knots.
What would you like to call the factor? 3? Call me a weasel, but I was hoping "roughly speaking an order of magnitude" would go down to 3. I suspected it was comfortably above 2. Am I right about that?
I'd call that half a order of magnitude, considering log₁₀(3) is around 0.477. So you're off by more than a factor of two.
0: Uniform, linear and logarithmic are obvious candidates, but depending on the domain you can end up with some really wierd scales (eg floating-point ULPs, which can look logarithmic or linear, but aren't either).
1: hence > So you're off by more than a factor of two.
roughly 10x going down to 3x would also mean it would go up to 17x. That's a pretty wide range, so I don't think that order of magnitude is going to ever really be similar to 3x of something on the basis of what it means.
In fact, the reversed kicking in would decrease the loading on the aircraft by decreasing it's airspeed.
This isn't a case of acceleration being able to break the mount from the frame. If it ever could, one wouldn't want it on the plane in the first place.
Doesn't mean you couldn't ruin your day with it, but it isn't an instant catastrophic failure either.
Read the accident report and follow up on Lauda Air Flight 004. Boeing specifically was forced to issue a statement that it was virtually impossible to overcome a catastrophic failure outcome from a thrust reverser deploying at cruising speed.