It could simply be offered in addition to the $1 subscription demo version.
Edit: I tried out by myself and I searched (for about 1 minute) on the RS website for a demo version - I did not find it. All I found is the 1 $ special offer. I searched even for a demo without subscription 1 $ stuff .... so the thing you talked about that other companies do ... the thing where you have to login and create an account (which is OK for me by the way).
Conclusion: It is not possible to get a demo version of Reason 13 without falling into the hands of the (1$ free trial) subscription model.
This company really seems to hate good software-workflow and customer centricity