There is an argument that the Greek translated as 'this generation' should not, in context, be understood in its modern sense of 'contemporaries alive now' but rather as 'this race, this people' or something similar; what the KJV translators would have had in mind.
I tend to agree with this. So I propose the following as a way of keeping the verse relevant to 1914:
'Our revised understanding is that 'this generation' means the new 'Spiritual Israel' which began to arise (or 'be generated') after CT Russell began to restore True Worship around the turn of the 20th Century. This group of Anointed Christians are the ones who 'shall endure till the end' (Mt 24:13)'