It looks like there are more Salesforce instances with the patch applied now - some EU, UW, and and CS instances. To the folks who have replied, please follow up when you have been able to test your communities, force.com sites, and Skuid pages following the patch, so we can forward this information to our contacts at Salesforce. Thank you very much for your patience.

We’re working again. I just finished testing things and looks like Spring '19 Patch 18.5 fixed everything. We’re on NA70 and customer and partner communities and force.com sites that were broken are now working correctly. 

Trust.salesforce.com shows NA70 is now on 18.5:

INSTANCE NA70

Instance Details Version:

Spring '19 Patch 18.5

Preliminary testing working for:

EU15

CS107

CS89

CS80

Prelimnary testing works for NA95.

Working on NA72

NA73 is patched already (Spring '19 Patch 18.6)

Noticed some Skuid components are loading, some are not, and some are not after a browser forced refresh (control-R in Firefox or Chrome).
Running Skuid 11.1.7

Seems to be back up for NA98, NA39, CS91, and CS77. 

NA73 is patched already (Spring '19 Patch 18.6)

Noticed some Skuid components are loading, some are not, and some are not after a browser forced refresh (control-R in Firefox or Chrome).

Running Skuid 11.1.7

Did more testing.  On the pages with the problem, it is only actually only loading 20% of the time.  These are pages with many custom labels (100+).  When I revert back to a version of the page without custom labels, it loaded 100% of the time.  When the page only has 1 custom label, it loaded 100% of the time as well.  This was never a problem before this incident.