https://insideevs.com/tesla-pushes-back-standard-model-3-deliveries-late-2018-early-2019/
I agree, this is a purely financial decision.
Right now a lot of reservation holders on other sites and forums are trying to convince themselves that the push up of Canadian Model 3 sales and the delay of SR version until Q4 is to keep from hitting 200,000 sales before July. This is supposedly going to allow more people to get the full or 50% reduced tax credit.
I really hope so. But unfortunately I don't think Tesla is going to be doing this.
At the moment, Tesla and GM are both at ~170,000 Plug-Ins sold. If S and X sales are static for the year, then in order to hold off the 200,000th sale into the 3rd quarter, Tesla would need to keep Model 3 US sales under 2,000 a month through June. That would mean only about 14,000 Model 3's would have been sold for it's first year in production. (July 2017 through June 2018). That would be a pretty bad first year for the Model 3.
Most likely, the reason they have pushed up Canada sales is because there aren't as many takers for the fully decked-out first production LR model in the US as they'd like there to be. The push up for AWD deliveries is for the same reason - lots of folks are waiting for the AWD option. So Tesla is going to move as many high priced units as they can as quickly as they can.
If they ramp up production in any significant way this quarter, they will likely hit 200,000 units next quarter. Tesla probably isn't actually concerned with any of us SR buyers getting the tax credit. They need to maximize their profits on this vehicle. It's what they probably should be doing.
Unfortunately this means that most of the people looking for the SR battery (without AWD) will be lucky to get the 50% reduced tax credit.