Some comments
A Solar Return chart can be looked at as a solar-solar eclipse. A real solar eclipse is, of course, an event in which the Moon blocks out the Sun in terms of where the viewer stands on Earth. In your case, you will have a special event in which Sun-Sun-Moon are all aligned. This is a powerful situation. The only additional factor that could make it more potent would be if this occurred at an angle in the Solar Return chart or the natal chart.
Looking at the Sun-Moon alignment upon your natal Sun, it would be prudent to look at where the Sun and Moon resides in your natal chart, how they aspect other planets, how they relate to each other, and which transiting planets on your S/R day aspect the Sun-Solar Eclipse point and natal Moon.
As a very general statement, you might expect that Moon symbolism (feeling, intuition, habits, family history) will become more pronounced and might change the Sun symbolism (will, intent, attitude, channeling of energies). A shift in your plans, a change in your character and how you lead or appear to others, etc. might be perceived in the coming year. Dave