TL;DR You will end up with a product that does not meet your business need, unhappy employees, and self-organising teams that are dead on arrial. Innovation will also suffer.
Impact on Product
Since the PO has responsibility not just for making a domain decision. They are responsable and accountable for the contents of the backlog.
That has to include not just your business needs but market trends and the commercial needs of your customers. Does your Dev Lead have deep financial and market knowledge? Is he making priority decisions on what the next most important thing to build is based on the whole picture?
That he is undercutting existing PO's shows a significant lack of respect for others in the organisation. That the CEO is supporting him, probably because of his magical technical prowess, shows him to be weak and have a significant lack of understanding of the software development process.
If you are building software products as an organisation it's your CEO's job to understand this, if you just build software to help you ... We'll... It still is...
Impact on self-organisation
Your employees and people thrive in the knowledge based world on three things; autonomy, mastery, & purpose.
The lead developer is undermining the moral and well-being of the organisation by putting this at risk. He has removed autonomy by making decisions on how things are to be done, this undermines mastery as the developers dont own the results. You may save mastery if the engineers are allowed to build good product, but I bet that's difficult in that culture.
Do your engineers feel that they are contributing to the overall wellbeing of the company?
Impact on empiricism
Each of the Scrum events are there to implement empiricism. Without empiricism we are still following a plan driven approach which we know is not effective.
The Sprint Planning event allows you to inspect the backlog and adapt the most effective Sprint Plan.
The Sprint Retrospective allows you to inspect the happenings of the Sprint itself and adapt the way you do things. This also affects self-organisation as it is owned by the team.
Removing these two things removes 2 of the 5 key inspect and adapt points in Scrum.
Without executive level commitment for agility and Scrum any digital transformation is doomed to failure. You need to get your CEO to understand the ramifications and significance of the changes and allow then to decide to be agile or not. It's their choice...but they should try to pick one and commit.
If they waver then chaos is the only winner.