Reasonably certain that the A/T FMA will remain at THR REF.
It's worth bearing in mind that the THR REF annunciation indicates the POTENTIAL thrust setting as distinct from a set value. Thrust can be set to any value up to, and including, the specific Reference Thrust, which could be, for example, TO1, CLB, CLB1 etc. What will be set, or adjusted to, will be dictated by the safe operating envelope. That reference value will alter with the various stages of flight and dependent on initial set-up inputs. What is active at any time is what appears at the top of the lower EICAS display.
In parallel with the above, it is worth noting that at least one, very expensive, computer-based training programme DOES NOT reflect real-life FMA's for non-procedural, ad hoc scenarios.