Currently, there appears to be an issue where renaming ResourceDictionaries can result in certain document's ResourcePanel displaying the old names of files rather than the new ones.

Video attached.

Repro Steps:

1) Create a new Project featuring a MainPage.xaml

2) In the Project Root, create a new ResourceDictionary named "Dictionary_Master_1.xaml"

3) In the Project Root, create a new ResourceDictionary named "Dictionary_Colors_1.xaml"

4) From the Resources Panel, merge 'Dictionary_Master_1.xaml' into the GlobalResources Dictionary.

5) Select 'Dictionary_Master_1.xaml' so that its tab is open.

6) Merge 'Dictionary_Colors_1.xaml' into 'Dictionary_Master_1.xaml'

8) Return to the Assets Panel, and under the Project Root, create a new ResourceDictionary named "Dictionary_Typography_1.xaml".

9) Open the Dictionary_1_Master.xaml tab, and in the Resources Panel, merge 'Dictionary_Typography_1.xaml' into 'Dictionary_1_Master.xaml'

10) Navigate to the Assets Panel, and renaming the following ResourceDictionaries:

Dictionary_Master_1.xaml --> Dictionary_Universal_1.xaml
Dictionary_Colors_1.xaml --> Dictionary_Swatches_1.xaml
Dictionary_Typoography_1.xaml --> Dictionary_Fonts_1.xaml

11) With the Resources Panel open, cycle through every open tab ('MainPage.xaml', 'Dictionary_Universal_1.xaml', 'Dictionary_Swatches_1.xaml', 'GlobalResources.xaml', and 'Dictionary_Fonts_1.xaml')

Observe how the Dictionary_Fonts_1.xaml is showing the old ResourceDictionary names, whilst all of the other documents display the updated names.
Observe how Dictionary_Universal_1.xaml is showing its old name for itself ('Dictionary_Master_1.xaml).

12) Close and re-open 'Dictionary_Fonts_1.xaml' and 'Dictionary_Universal_1', and inspect their Resources Panel once again.

Observe how they now features the correct updated names.

Expected Results: Renaming Resource Dictionaries updates their names in every instance where they are referenced.