Nothing unlawful or improper here.
He also met with Russian sovereign wealth fund manager Kirill Dmitriev during the transition period—a meeting reportedly planned to set up a backchannel between the Trump administration and Russia.
Transition period = AFTER Trump won the election, where he is now the President-elect, and expected to start setting up his relationships with foreign powers.
But don’t you know, it is expressly FORBIDDEN that Team Trump make ANY overtures to any foreign powers anywhere or at anytime.
I don’t know who set that rule, but the Democrats and the Mueller Star Chamber certainly is working overtime to apply the spirit of the rule, wherever it may lead.
Of course, if it does not lead to Trump being impeached, the path is quietly abandoned.