The only difference I see between the 2019 and 2020 Step-thru is that the 2020 model has a new headlight.
That makes $999 for the 2019 model a very good deal.
It's a little more than a headlight, but not by much. Here's my analysis...
So, am I missing out by not spending another $500+ for the new model? No.
The only difference between this and the new model are:
Mounts on frame for wheel lock - Can still use any traditional bike lock, and wheel locks are very low security as bike can still be rolled/carried away.
Updated handlebars - Personal preference. New model seems SLIGHTLY more swept back, but a local bike shop can switch your handlebars for much less than $500 is that's what you want.
New halo headlight for optimal side visibility - Stock headlight is fine, and rechargeable add-ons are more visible and cheap. If you must have a Halo, rumor is they will be an easy retrofit and much less than $500.
Streamlined throttle design - Unconfirmed, but this is probably just the removal of the defeat switch as on the RadRunner. Probably more to save Rad Power costs than a benefit to the rider as it's actually removing a feature, but might make it slightly easier to reach rear shifter.
New finish and decals - Zero Benefit, and actually makes the bike slightly less visible.
Rack Redesign (Not listed by Manufacturer) - The supports on the rear rack are slightly different. So slight, the manufacturer didn't even mention them in the "What's New" rundown.