I dont believe there will a material change to terms and conditions (certainly at the bigger end of town). I dont remeber seeing any significant improvements to T&Cs directly attributed to a pilot shortage in the past, so unless pilots buckle under threat I dont see an adverse change now.
The quality of the new hire will improve, and all that really seems to happen in more prosperous times is that anyone with the ever reducing requirements seems to get a job.
A minority will find lucrative opportunities outside of aviation, but most will given a realization of how good they had it in aviation despite the many drawbacks.