Hello,
A simple answer is that yes this "should" work but has not been tested or qualified by HPE. However, you should consider several things when migrating your data. With ESXi 6.0 virutal volumes are supported but not with ESXi 5.5. Likely that is also true on the storage side. You did not mention the older device, but likely it is a linear based storage device while the MSA2050 is virtual only. To take advantage of the array and the host OS your best bet would be to move to all virtual.
Just as a precaution - your new system has at least a warranty support contract available on it. If you are not in a supported configuration, your warranty options will be limited.
Without knowing your environement, my concerns would be compatability between your old storage and new. Can you VMotion the data over successfully? And if you can get your current data to the new MSA 2050, your next question to consider would be can you connect a newer ESXi OS version to the MSA 2050 with your data's file system intact? In other words are the OS versions compatable between VFMS5, VFMS6, etc?
You might want to consider future growth and how you want to implement this so you do not build yourself into a corner. It might make more sense to backup your data and start fresh so you have the ability to expand into newer OS and storage options as needed. Sometimes a little pain at the start saves you major heartache at the end.
Good luck!
Cheers,
Shawn
I work for Hewlett Packard Enterprise. The comments in this post are my own and do not represent an official reply from HPE. No warranty or guarantees of any kind are expressed in my reply.