The Ab in the cello part in the final chord of the music you posted is almost certainly a typo. The entirety of the piece aside from that is written with typical common practice harmonies that you would expect to see in a theory class.
The only context I would expect to see the music played as written would be a mistake on the part of the cello player or typesetter, or a bizarre piece of performance art that exists to make the audience cringe when the cello plays the last note. IIbmMaj7
chords do not exist in Theory 101, and when you see that combination of notes in a theory class, you're not going to be calling it a IIbmMaj7
chord anyway (you'll be calling it a 0-1-4
pitch class set).
It's supposed to be a G natural in the cello part, making the final chord a perfect authentic cadence on the I
chord.