Late last month, the vivo X300 Ultra got certified for sale in Europe, basically confirming its rumored global release. Now, the phone has been certified in Indonesia by TKDN as well. It has the model number V2562, which was confirmed to be attached to the X300 Ultra name all the way back in November. So it's pretty much settled at this point - the X300 Ultra is going global.
Historically, the top-end Ultra from vivo's X series flagship phones has been reserved for the Chinese market, but this is likely to change as we now have strong evidence that the yet-to-be-announced vivo X300 Ultra will make it outside China this year. According to the GSMA database, vivo might be preparing an international version of the X300 Ultra because the handset has appeared with a different model name that doesn't match the usual naming scheme for vivo's Chinese handsets.