That's not a very convincing lever in a negotiation. The final relationship will benefit the EU far more than the UK, simply because of the balance of power, regardless of delusions to the contrary and empty bombast from Johnson.
A bill passed its 3rd reading in house of commons. It needs to get through the House of Lords. It still has some way before becoming law.
https://www.parliament.uk/about/how/laws/passage-bill/common...
And when the UK crashes out of EU with no deal we'll inevitably re-allow free movement of EU workers because we have no bargaining power.
Regarding your last sentence: leaving no-deal off the table, and this being unable to walk away, would have meant we have no bargaining power.
It’s incredible how many times people have cried wolf about this.
There's no version of the UK in 2022 that doesn't have freedom of movement for EU citizens.