@ SCHOLAR: you said, "a 'great tribulation (without the definite article) would foreshadow... 'the great tribulation' in Rev. 7:13, 14."
Are you saying that something which Jesus said would never be repeated, (Matthew 24:221) was going to have a another fulfillment, a greater one? If so, your org's dogma is telling people that Jesus was wrong.
It's not reasonable to claim that different scriptures are discussing the same topic simply because the wording is similar.
Acts 7:11 also speaks of a "great tribulation" but the surrounding verses and context eliminate any connection to Matthew 24:21.
Contextually, tie in Revelation 7:14 with Revelation 2:22. The words spoken were about 8 minutes apart.
Connecting statements from the same book of the Bible and from the same discussion, makes far more sense.