I recently watched a televangelist interview several other evangelists on the subject of salvation following the rapture (all were pre-trib) and I think 5 out of 6 said they did not think scripture supported the idea. The subject of those serving Him in His temple day and night didn’t come up, nor the mention in Revelation of those that were slain for not taking the mark arriving in heaven. What alternate interpretations of these verses could possibly support their views that no one will be saved during the tribulation?
I think the Bible clearly supports the fact that many will be saved during Daniel’s 70th Week following the rapture of the Church. You’ve mentioned Rev. 7:9-17 and Rev. 20:4 as two examples. Rev. 14:12-13 and Rev. 16:15 also speak of believers on Earth during the Great Tribulation.
I think some teachers are reluctant to mention the possibility of post rapture salvation for fear that those who are undecided will see this as an excuse to put off making their decision. But in doing so these teachers deprive many believers of the hope that friends and loved ones who are left behind will see the rapture as the sign that finally convinces them to give their heart to the Lord.