Just consider Southend in the last 3 years.

In the first year they were drawn against someone- it doen't matter who.

In the second year the odds are 1 in 72 that they would be drawn against the same team. Ditto for the third year. (Assuming that nobody leaves or enters the league, have fun correcting for that).

So the odds for "three in a row" are 1 in 72*72 = 1 in 5185

That looks like quite a coincidence.

On the other hand there are equally dedicated writers for all the teams.

If, rather that Southend, it has been Example United who had been drawn 3 times in a row against Madeupname city ten we would have heard from them instead of you.

So there are 72 teams who, if they had a coincidence like this, might have written in. That drops the odds by 72 fold (I think).

So the odds are just 1 in 72. Not that spectacular.

Incidentally, the real answer is that since it has happened, the probability is exactly 1