It’s notable that Loeb describes an acceleration away from the sun but doesn’t tell us its magnitude, which would be quite easy to calculate from observational data. If it were simply due to gasses escaping at its surface due to heat from the sun, the magnitude would be quite low. If it were, for instance, energy from a nuclear thruster, it would likely be much higher. It’s my opinion that it’s the former, and Loeb simply wants his fantasies to continue until it has disappeared forever.
I read some of the work on the observations. The acceleration is extremely low, in line with what could be expected from outgassing.