I agree with you; the biggest surprises of the tournament so far have been in Group E. If Belgium suffers another defeat, they may not be eliminated because they can still qualify out of the group as the third-placed team. However, this situation would make their job harder. Considering today’s performances, it is possible that Ukraine will finish last in the group, and Belgium will end up third.
This is just their first game and I think it is way too early to judge them base on this performance today alone, The game is still open and Belgium can still come out top in their group if they win all their remaining matches from here despite that they lost in today's game but the correction may come in their games ahead, and I still doubt Belgium won't qualify for next stage of this competition.