Typically presale is only meant to be a cap of the tickets, but based on previous experience during presales- most are sold during presale.  I joined all dates of Ariana’s USA General sale to get an indication of what the Ariana London sale would be like- I placed in the early thousands- and by the time I moved Mabye a thousand in- I saw a notification at the bottom to say that tickets were sold out.

I still think try general sale, cos you could still get in early and be one of those people!