The permanents will enter while Morphic Tide is face up. This means the game won't be on any plane when determining if any abilities trigger because those permanents entered, for example. However, you'll planeswalk away from Morphic Tide before any such abilities are put on the stack. After you turn the next card of the planar deck face up, any abilities that triggered during the resolution of Morphic Tide (including any abilities that triggered because you encountered another phenomenon or planeswalked to the next plane) will be put on the stack. The planar controller will put their abilities on the stack in any order, followed by each other player in turn order. The last ability put on the stack will be the first one to resolve.