According to the Website WES7 SP1 support will end in 10/13/2020, which is also an end of ship date. An OEM can no longer ship new products with WES7 SP1 after that date. Sometimes there are wavers depending on the OEM and product.
I suggest that you contact Microsoft distributor for more information. I would recommend moving to Windows 10 IoT Enterprise now rather than later.
Sean Liming - Book Author: Starter Guide Windows 10 IoT Enterprise - www.annabooks.com / www.seanliming.com