Definitely stable. I took a 2001 Honda RC51 (aka RVT1000R in other markets) to 145 mph twice and I found that it only wanted to go straight and no amount of rough surface and bumps upset it. If you're on the throttle that hard, the bike just wanted to stay upright and go straight.
When the highway curved gently, I was surprised how much I had to lean at that speed to get the bike to follow the road and stay in my lane. Major respect to those GP racers who go around twisty tracks at that speed by hanging off the side of their bike and quickly flipping over to hang off the other side to negotiate those turns.
That’s a longer fork rake angle on high speed flyers to give you that straight line stability. Twisty bikes have that angle set lower.