Whether the WA is as of now voided, is the grist to lawyers mills . But yes that is the potential situation. A significant number of senior Civil Servants and ex PMs are voicing those concerns.nobody is talking about voiding the WA. Dispute resolutions are there for disputes like those arising from a no deal, where both sides can negotiate on variations to the treaty.
My point is, the UK needed the one year of transition. The EU is interested in long term relationship where its size can give it some advantage. The UK side only wants to start small then see later how the future shapes up.
You make a deal with a Chinese company for 1000 bikes complete with a detailed specification. They decide ,for no good reason , and deliver all the bikes now in a bright gay purple..a colour which will not sell, in deepest Somerset rather than the tame pale blues and teals, which was specified. .. Do you pay?. Moreover in your contract ,you had a dispute conciliation process.. in engineering terms Engineering Change Notification, which they never implemented.. because they suspected that you would never sign off on purple bikes . Would you deal with that company again?