Microsoft's documentation on Design Manager mentions steps to import design package & the content it brings in. It also recommends not to deactivate the feature in solution gallery - /_catalogs/solutions/Forms/AllItems.aspx - which may lead to deletion to content types, eventually leading to issues in pages associated with page-layouts.
From branding perspective, It's very common practice that branding evolves over time & development team needs to plan to push newer version of package on existing sites as well. Documentation on upgrade scenarios - Do's & Don't - is missing from MSDN.
Observations:
- Every newer version of package imported on site is a separate entity & same can be found in solution gallery. The features for old versions remains activated may imply there is no relation between old & new versions.
- Change in site columns, content types reflects at the site level after import of newer version but pages libraries where the content type was already present, doesn't not refresh for new columns, change in column properties. Moreover, any existing artifacts e.g. page-layouts are not refreshed for changes.
Does anyone has in-depth knowledge of how branding package responds to upgrade? What are Microsoft's recommendation on package upgrade & how to ensure artifacts are refreshed? Without upgrade option, design manager becomes pain if we've to push the changes for add, update & delete through Power-Shell or some other mechanism than design manager taking care of it.
I have looked everywhere and I couldn't find any Microsoft best practice regarding upgrading design packages However I have been re-uploading design packages normally on almost every project I worked on with no issues.
you just need to upload the new package then run a powershell script to publish all content inside your masterpage gallery and style library much like this article: https://www.rightpoint.com/thought/2015/10/19/publish-everything-in-the-master-page-gallery-with-powershell
Do not deactivate the old package. it shouldn't cause any issues. Old package files having the same name will be updated and the ones that are not will stay untouched.