A sliver of hope is still better than nothing. Longbridge should be glad at the very least, there's some hope. Even if Nanjing has the capabilities of Toyota, it'll still take some time.
The only way Longbridge will eventually get back to the glory days is for MG to quickly become wildly popular, not just in UK, but all over Europe and US. Then Longbridge can build the cars to meet the demand of those markets.