Plan Sponsor is an ESOP - testing?

We have a 401(k) client where the plan sponsor/corporation became owned by an ESOP in 2017.  I don't know any more about this transaction other than the company is now owned by an ESOP.  This company has sponsored a 401(k) plan and still does during 2017.  

Some research I did indicates Code Section 318 states that the constructive ownership of stock does not apply to shares owners by a 401(a) employee trust which is exempt from tax under 501(a).  So it seems since the ESOP is the owner of the company, the 401(k) plan no longer has owners for purposes of HCE and key employee determination.  All shares of the company previously owned by all the family members are now owned by the ESOP and don't attribute to them personally is my take.  The plan is subject to ADP testing but perhaps will be a non-issue if attribution does no exist.  I also have to question whether officers exist for top heavy purposes.  the plan is a long way from being top heavy thank goodness .  I'm told there are board members of the ESOP but the client is implying there are no longer officers.  If this is the case there may be no testing whatsoever.  But I'm approaching this with much caution! 

Comments anyone? Thanks

If there needs to be testing or not is a complex issue. 

It is true that if an ESOP owns 100% of the stock there are no individuals who are shareholders.  The trust owns the shares not the individuals. 

If the stock was sold during 2017 as long as a person owned the stock for 1 day they were a shareholder in 2017 for this purpose. 

You can be an HCE by compensation also. 

It is hard to imagine there are no officers in a company so it is a question of compensation for Key Employee.  Oddly, this could mean you have a bunch of former Key Employees for the TH test also. 

Don't forget the look back year for ownership. 

So if the stock was sold in 2017 those people could by HCEs in 2017 and 2018.  In 2017 as a current year owner and 2018 as a look back year owner.