The Linux kernel configuration help says this about XFS version 4:
CONFIG_XFS_SUPPORT_V4, "Support deprecated V4 (crc=0) format"
The V4 filesystem format lacks certain features that are supported by the V5 format, such as metadata checksumming, strengthened metadata verification, and the ability to store timestamps past the year 2038. Because of this, the V4 format is deprecated. All users should upgrade by backing up their files, reformatting, and restoring from the backup.
If this large amount of data is expected to be long-lived, the year 2038 is not so very far away any more. However it is likely that you'll need to upgrade your hardware at least once or twice before that; you should keep in mind that the filesystem version migration needs to be done at some point before that year. It might be most convenient to do the filesystem version migration together with a hardware upgrade, if you plan accordingly.
As time goes on, the distributions might even remove the support of the XFS version 4 well in advance of the cut-off year in their new major releases, so eventually a big OS upgrade might force you to do the migration anyway.
As far as I know, XFS version 5 has turned out to be very stable with no particular issues.
Just be aware of this in your long-term planning for now.
Newer kernels have already started to warn about the timestamp limit of the XFS filesystem when appropriate. With them, you'll see a message like this from the kernel in
xfs filesystem being mounted at <path> supports timestamps until 2038
Depending on the version of tools used to create the filesystem, even XFS V5 filesystems might cause this warning. But on XFS version 5, that can be fixed without a backup/restore cycle by running
xfs_admin -O bigtime=1 on the filesystem while it's unmounted and error-free. I've recently done that on a Debian system after an upgrade from Debian 11 to 12 - the operation was quick and trouble-free.