It looks as though the complaint filed with the Federal Election Commission by the National Legal and Policy Center against Alexandria Ocasio-Cortez, Saikat Chakrabarti, and several entities among the web of nonprofits that financed and guided her campaign is being taken very seriously.  Andrew Kerr of the Daily Caller News Foundation noticed that official papers filed with no fanfare last Friday may be aimed at allegations in that complaint by removing the two from the board of Justice Democrats, the nonprofit co-founded by Chakrabarti with the aim of recruiting attractive radical left-wing candidates for Congress (see this article by Frank Hawkins for background).

Kerr writes:

The New York Democrat and her chief of staff, Saikat Chakrabarti, who served as her campaign chair, joined the board of Justice Democrats in December 2017, according to the political action committee's website.  It also said the two held "legal control over the entity" at the same time it was playing a key role in supporting Ocasio-Cortez's campaign prior to her shock victory over incumbent Democratic Rep. Joe Crowley in June 2018.

Attorneys for Ocasio-Cortez said she was removed from Justice Democrats' board in June 2018, but she was listed an "entity governor" of the PAC as recently as March 14, according to corporate filings, The Daily Caller News Foundation previously reported.  (RELATED: Ocasio-Cortez Has Ties To A Dark Money Group)

Ocasio-Cortez and Chakrabarti were officially removed from Justice Democrats' board on March 15, according to a corporate document filed that day to the Washington, D.C. Department of Consumer and Regulatory Affairs.

Ocasio-Cortez dining with Chakrabarti, who enjoys a hamburger (source).

If I understand this correctly, they are claiming that Sandy severed her relationship with the PAC, but they just forgot to file any papers to prove that.  This is important because:

Ocasio-Cortez never disclosed to the Federal Election Commission (FEC) that she and Chakrabarti controlled Justice Democrats while it simultaneously supported her primary campaign.

PACs are allowed to raise funds from donations much larger than are allowed for money given directly to campaigns.  But in return for this freedom, they must be independent of and not coordinate with the campaigns they support.  The stakes are very high:

If the FEC finds that her campaign and the PAC were operating in affiliation, it could result in "massive reporting violations" or potentially even jail time for Ocasio-Cortez and Chakrabarti, former FEC Commissioner Brad Smith previously told TheDCNF.  Another former FEC commissioner, Hans von Spakovsky, wrote in a March 10 Fox News op-ed that he believes there's sufficient evidence to "justify opening a criminal investigation" into Ocasio-Cortez.

Left-leaning Snopes has been receiving statements from lawyers for the defendants and presents their claims about the complaint, revealing, among other things, that the web of organizations started by Chakrabarti and associates may have been something less than outright discrete entities:

In their statement, attorneys for Ocasio-Cortez explained that Brand New Congress LLC and Brand New Campaign LLC were one and the same entity, and that Brand New Campaign LLC had simply changed its name to Brand New Congress LLC.  They also confirmed that Chakrabarti had been the the owner of that private company.

Malleable names and identities for groups are sometimes a sign of hanky-panky.  The FEC will have its hands full sorting out the changing universe of groups and leaders involved.