What is being proposed here is a standard non-compete contract--you can't take your knowledge and work for my competitor--ok with me in this situation, but many of which have been held to be unenforcible. But this also completely ignores there real issue, which is actually what you were doing before and if you are going to continue your lobbying inside the White House. It is one thing to bring your ideas to the White House, everyone has those, but other thing completely to continue your work for a private group.
Lobbyists have been a large part of politics for a long time. While they have had their uses, government might be better off without their influence and "assistance". This could prove to be a beneficial thing to politics if some of the focus is taken away from money in campaigning.
Trump has already included lobbyists in his transition team. I find it very hard to believe that he is going to swear off all lobbyists during his time as president. As a matter of fact, there is a lot of talk about how he will employee lobbyists for his own personal gain, which is the type of thing Trump is known for.
No, nothing is likely to change much due to the Trump Administration's plan to ban lobbyists. First, it is unreasonable to expect that a ban on lobbyists will even take place. Lobbyists serve an important purpose and their can't be eliminated. They also are a very powerful force. Trump will not be able to successfully ban lobbyists.