I guess their extradition case in Canada must not be going too well for the US if they have to cobble together some new charges like this.
Current status of the Meng Wanzhou case in Canada is the case has to pass the hurdle of proving "double criminality" when Canada had no equivalent Iran sanctions in force (as Canada was backing the European treaty with Iran). The next hurdle is an abuse of process hearing regarding how she was held and questioned at customs and immigration at the request of the US. Neither of these is decided yet, but there are reasonable grounds for the case being thrown out on either one. And that isn't the end of the story either.
It is possible that this new development may be "Plan B" for the US, as it avoids the rather shaky "double criminality" question and short circuits the very unsavoury details surrounding the abuse of process events.