Here is a full text (source - https://camelotunchained.com/v3/the-not-rob-but-someone-else-on-fire-edition-friday-march-15th-2019/
Discontinuing the 32bit Client: Moving the game client to 64bit has been a big boon to what we can do with the engine. However, that means we need to discontinue support for the 32bit client. If you have an old machine, most hardware is 64bit, but you may have a 32bit Windows install. If you currently are running a 32bit version of Windows, this will affect you, and you will need to install the 64bit version of Windows to continue playing CU after April 15th, when we plan to make this change.