From semantic-mediawiki.org

Configuration parameter details:
Name $smwgRSSWithPages
Description Sets whether RSS feeds should deliver whole pages or just link to them
Default setting
Software Semantic MediaWiki
Since version
Until version
Configuration RSS export · inline queries
Keyword rss · export

The configuration parameter was introduced in Semantic MediaWiki 1.0Released on 31 December 2007 and compatible with MW 1.9.x - 1.12.x. and removed in Semantic MediaWiki 1.8.0Released on 2 December 2012 and compatible with MW 1.17.0 - 1.22.x
(except 1.22.1).
meaning that RSS will always deliver whole pages.