Completely expected. Trump doesn’t really have a good track record in coming up with legal executive orders, while Tiktok is completely in their rights to contest this order. And...judicial review is what sets the USA apart from China.
Whether you think it's right or wrong, legally, it has prescient.
In this case, the order bans any US citizen from doing business with ByteDance, and doesn't make a carve out for retaining a US lawyer, which is a violation of due process and means a judge could overturn the order.
If they just added that carve out, it would probably be entirely legally defensible. That one dumb mis-step could mean it gets overturned. This keeps happening with the Trump admin, it's the same reason the DACA repeal was overturned by the supreme court.
It absolutely is.
Trump does not seem to posses that ability. His strengths in in completely different areas.