If you edit a simple template, for example {{1x|foo '''bar'''}} in VE and re-render, the top-level text nodes of the template disappear if you are using jQuery 3. In this example, the template renders as "bar" and the "foo" disappears.
Tracing through the problem, it seems to be this line in ve.ce.GeneratedContentNode.js method getRenderedDomElements:
$rendering = $rendering.not( 'link, style' );
In our example. $rendering would contain [ <text node>, <b node> ] prior to this line.
In jQuery 1.x (ie, in production), this preserves the text nodes, and the result is an array of length 2.
In jQuery 3.2.1, the text node is removed (presumably because it is not an Element) and the result is an array of length 1. This causes the rendering to lose those top-level text nodes.