Previous results do not impact the odds of a single future event. So you are correct.It doesnt really matter.
Ultimately, the reason 'its hard to beat a team 3 times' is that even if you have 70% odds to win, over 3 times, odds say you'll probably lose one. However, each time, the odds individually are still 70% that you'll win. So looking at it at the beginning of the season and having 70% odds, you'd probably say 'yeah, we probably wont win 3/3', but if you've already won 2/3, your odds on the remaining one are still 70% (same for 60% or 50%)