Self explanatory. More like an issue than a bug but it would be nice to have 64 bit worlds in vanilla, considering that real infinite worlds are possible with BigInteger (albeit with preformance compromises) and long values. Someone has already technically done this in 1.2.5 and it worked just fine. Basically, the 30 million limit in current minecraft is much too small, and considering most modern processor can handle values up to 9.223 quintillion, I think Mojang can do better here.
MC-223038
Worlds are still only 32 bit
Resolved
Invalid
0
While 64-bit coordinates are cool with mods, it's too much work for the people at Mojang to make it 64-bit, and it would create a whole new set of bugs. It would also cause issues for people attempting to run Minecraft/Minecraft Servers on older processors. The 30 million block limit of Minecraft is big enough even for servers like 2b2t. As said in the description, this is not a bug, this is a feature. I recommend you send this in on feedback.minecraft.net. It would also cause parity issues with Bedrock Edition which only supports 32-bit in order to run well on older devices.