So, after some time on wikiperdia:
Judo = 14 weights total 7 mens 7 womens
Weightlifting= 10 weights total with 5 men's and 5 womens
Boxing = 13 weights total with 7 men's divisions and 6 for women
I see no way we get more weights considering we already have the most by far. Maybe if a style is cut we can add some weights to the remaining two styles.
The only avenue I see, and it is a super long shot, is that with all these transfers from places like America and Russia winning medals for non-wrestling countries, the olympic committees of those countries start advocating for more weights for wrestling. Highly doubt it happens but that is the only way I see us going above the current 18.