Missing dm-thin-pool kernel module with Ubuntu 18.04 deployment

Hi recently upgraded from Maas 2.4 to Maas 2.5 and now encountering error when deploying a node with Ubuntu 18.04.

$ uname -a
Linux joe 4.15.0-46-generic #49-Ubuntu SMP Wed Feb 6 09:33:07 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

The deployment fails because the dm-thin-pool kernel module is missing from the cloud image installed by Maas. Indeed that module is missing from /lib/modules/4.15.0-46-generic/kernel/drivers/md while it’s supposed to be there unless I missed something… I googled around to find that this module is installed by linux-modules-4.15.0-46-generic_4.15.0-46.49_amd64.deb. That’s probably not a package I should install via the presseeds (or should I ?).

Directions about how to solve this issue would be highly appreciated.
Thanks
-P