Warning: 2.4.0 is coming. What it is changing and you must know

What old plugin install have to do to accomplish with new 2.4.0?
Substantially nothing, except for setting up on phpBB ACP options to avoid user’s email updates in phpBB and new registrations (read instructions) on how to achieve, or choose how to integrate in different ways, may allowing the same only in phpBB side. You have to choose in 2.4.0. Login, registration and email update, ONLY in WP or phpBB. NOT BOTH.
There are possibility to mix up things, as you can may argue reading help install pages (especially reading the phpBB to WordPress way to integrate, to understand more deeply)

https://www.axew3.com/w3/wp-w3all-wordpress-to-phpbb-install-and-how-to/

Please read the above, and if you want to test out new coming devel 2.4.0 version it is here:
https://www.axew3.com/w3/forums/viewtopic.php?f=2&t=1591&start=40