Kanye will be standing against Trump, as an independent candidate. This in itself should be proof alone that he is not working in Trump's interests, or as part of his campaign.
West's Presidential ambitions predate his friendship with Donald Trump. When he first announced his intentions to run, he said he would stand in 2024 - a race that Trump, unless he loses in 2020, will be legally barred from entering. In this case, his current election bid cannot be seen as a simple ploy to get Trump voters.