Yes, it changes things a bit. Parties in their manifestos say what they would like to do, but after the election, if there is a coalition government, that's just their initial bargaining position. No party can expect to get everything of what it promised. In a way, that's part of the idea of proportional representation, that if a party gets only 20% of the votes, they can't really expect to implement their entire policy. They're going to have to make compromises with other parties and they put together something that every party in the government is compatible with.
On July 26th, 2016. See this statement in context.