Kikar is reporting on a story of a yeshiva bochur who just got married, but because he was breaking the yeshiva's rule of what the acceptable minimum age for marriage is, the rosh yeshiva did not allow the other students to attend the wedding.
The yeshiva says boys can get married only from age 22. This boy was 21 and decided to get married anyway. The yeshiva threatened everyone else that whoever participates in the wedding would be tossed from the yeshiva.
It seems the rosh yeshiva doesn't agree with the recent decision of the rabbonim in the USA who have called for boys to get married at 21 as a solution to the shidduch crisis.. not that he has to...
While it seems ridiculous to punish a student who has been in the yeshiva for 3 years in such a manner, not allowing his friends to attend his wedding, it is not the first time such threats have been used to promote yeshiva policy. The same way taxation and public policy is used to engineer social change and promote priorities of the government and society, yeshivas make these sorts of rules as well.
I know of a yeshiva (from a cousin who married a boy from that yeshiva) in which the rosh yeshiva allowed its students to only get married in certain months of the year and only on certain days within those months. Anybody who got married outside of the acceptable date - would be out of the yeshiva and his friends would not be allowed to attend. The rosh yeshiva didnt want weddings to be at any given time disrupting the schedule of the learning in the yeshiva.
This rosh yeshiva, in the story above, is doing the same. He wants boys until a certain age worried about learning and not about dating. I feel bad for the boy, but he knew the rules and decided to break them. Sometimes you get away with it, and sometimes you don't.