According to WABetaInfo, the WA app can have 1024 people in the chat but will not be rolled out widely.
For a long time, WA group strength stood at 256 participants which was good for classroom and chatting with a close circle of friends but was getting limited. Hence the group chat number was raised to 512 just a little while ago and once again it is going to be doubled to 1024 members.
However, the new feature is not available for all, just a limited few can access it and it is rolled out on iOS and Android devices. If you are the chosen one, you will be able to see the upgraded version while creating a group.
The new feature is in no way different from the existing one; more people can see the chat and reply and vice versa. However, Telegram, the WA competitor, already has a feature of 200,000 members in a group chat making the new WA service insignificant.
Having a large group chat is more convenient for broadcast and business purposes than personal-level messaging, as reading and replying to such a large group is challenging. It is believed that the app is working on tools to make the large group manageable like requesting approval before joining the group.
You will need to enroll in the Whatsapp Beta for creating a group having 1000-plus participants and only if you are the chosen one, will you be able to access the new upgrade.