I agree. It's better to cut off the line past the point where it no longer has any data to support it.

In this case it's about 2.5 years of missing data that is substantiating a claim of 2x+ increase during the same time. It's reasonable to say it had an exponential function up until two years ago, and we don't know what it was since then.

R squared doesn't capture that inaccuracy because there is no data to compare it against during the scary time period in question. It's just a line in a void.