If you do not need the full new sata drives data size limits
Because.
1 In the the future, you might want to replace drives in the computer with newer faster drives that may only come in smaller drive sizes such as solid state drives.
2 In test i have run, the first 50 to 70 percentage of a drive far out perform the last 30 percentage of a drive of a drive.
3 By not having such large drive space on business server, it will force you to place other data not necessary to be on the server on some other kind of media, making it easier to manage the server. If you could move large amounts of data to and from a drive fast there would be no problem, but a large amount of space on a server will temp you into placing data on the server that is maybe more likely than not better achieved else where.
4 Smaller drives usually cost less and it should be easier price wise to justify in stock piling a few in case of drive problems.
5 You can expand the drive later if really necessary.
6 If you want to reduce the data partition of large drive that once held large amounts of data and now has much less, you will not be able to do that, unless you can somehow defragment the drive.
This is all for reasons of data management and time management, and not because sme server cannot handle large drives.