For example, after this week's election, could parliament say "Hey, the referendum and subsequent parliamentary vote were relevant to a time in the past. It has nothing to do with us and we are not doing it".
Are future UK parliaments (i.e. election this week) bound by decisions of previous parliaments regarding the Brexit vote (among other things)?
No. However, they are bound by the fact that the United Kingdom already triggered Brexit. So they would have to find a way to cancel the Article 50 request. No one has ever tried to do that, so someone would have to set precedent.
There's also the problem that both major parties are pro-Brexit at the moment. Only the Liberal Democrats are suggesting that they would cancel the Article 50 request if Europe lets them do that.
So on Brexit, the answer is unclear.
If you generalize, then parliament is not bound by its previous decisions. It can certainly repeal previous decisions. That doesn't help it though if the previous decision was a ratification of a foreign treaty. Treaties don't care about different parliaments. A treaty is either ratified and binding or it is not.