Hello - Some good news about the 10.9 release.
I am able to save hosted feature layers that have had schema changes applied. Last night I needed to add an attribute field to store length on some utility line features, because at the moment the SHAPE_Length field in Portal 10.9 Hosted Feature Layers cannot be used (for statistics) in the 10.9 Portal Dashboards, at least in my current 10.9 deployment.
Nor is the field recognized in the AGOL Dashboards (for statistics) when the layer comes over as a collaborated layer. For me, the Indicator would display a 'Cannot Access Data' error icon.
The SHAPE_Length field in ArcGIS Online Hosted Feature Layers CAN be used in AGOL dashboard statistics indicators, at least that's what I found by testing.
Soo... after overwriting my SD and hosted feature layer with the Pro2.8 sharing module, the new attribute was included with the layer but was not visible. When I initially tried to save the layer changes from the ‘Visualization’ tab that you access from the layers overview page, it would not save. It would just keep showing as not saved (i.e the 'Save Layer button does not go inactive - again at least for me in this deployment).
So I tried adding the layers to the Map Classic Viewer, went into the popup config, checked the attribute visibility, sorted as needed, and then hit 'Save Layer' from the layer menu in the TOC.
It worked! My layer saved with my newly added attribute visible, and now our staff can once again use a Length field in Dashboards. Yay!
@JonEmch thought you might like to know....
I'm glad to hear that this workflow worked out for you David, and I will take note of this in case someone runs into this in the future. Thank you for keeping me in the loop!