My guess is that the original plan was always for 4 months to...

My guess is that the original plan was always for 4 months to complete scoping and then execute MOU (I firmly believe backstage scoping is already complete) . However, Total wanted to progress with DFS (playing safe and risk averse? ) as well which is why we are seeing this delay in the announcement. PRL being the junior player succumbed to this demand and now saying it was a typo and that MOU is for 12 months.
If you read their July ann in which they provided all the updates, it clearly says Partners' intention

The HyEnergy Partners MoU runs for a 12-month period from April of this year, however it is the Partners’ intention to have a Scoping Study completed, Definitive Agreements executed and the Feasibility Studies advanced well within this time period.