1919 does give them more time than 1914 because it is not tied fo “this generation”.
1919 simply marks the re-establishment of pure worship and the endtime can stretch from that date indefinitely.
Keeping 1919 affirms the authority of the GB-faithful slave chosen in that year, without tying them down to 1914-generation teaching.
For example Seventh Day Adventists believe the endtime and investigative judgement began in 1844 and continue to stretch this out.