I just followed the proposal for an Arabic language in Area 51, but am not shown in the followers list. This might be a bug.
As I commented and you said resolved the issue:
There are two email verifications you have to do if you're a totally new user on the network: one for the overall SE network, and a separate one for Area 51 specifically. This is a historical flaw resulting from the fact that Area 51 runs on an old code base plus a bunch of later ad-hoc fixes.
The process is detailed in this Area 51 Discussions answer. I've commented on why this is the case there:
Some insight as to why this process is super convoluted: Area 51 runs on an old (2011) fork of the Stack Exchange engine. Up until October 2018, it had its own separate login flow, which only required one email verification explicitly for it. (Back in 2011, the main sites didn't require email verification, but the devs implemented it explicitly for Area 51). Since then, two things happened: the main sites started requiring email verification, and SE removed the separate login flow for Area 51 and routed it through Meta Stack Exchange (as part of a broader rework to remove OpenID support).
So what you see today is a bunch of ad-hoc fixes: as the login flow is today routed through Meta.SE, you have to verify your email with it first before it lets you create your Area 51 account, then once that's created, Area 51 requires its own email verification process that is a legacy from the time main sites didn't require it. tl;dr - it's a perfect storm resulting from Area 51's legacy 2011 code base combined with a bunch of ad-hoc fixes to resolve specific issues as they came up.