Hi Rafael,
Yes you still need osmo-msc<->osmo-bsc_mgcp and osmo-bsc<->osmo-mgw.
Related task is [1].
As far as I know, the work to use osmo-mgw with osmo-msc is mostly done and available in [2], but it has not been yet merged because some automatic testing bits are still missing.
[1] https://osmocom.org/issues/2605 [2] https://gerrit.osmocom.org/#/c/4980/