Nope. Hitler wanted Britain as an ally.
Had Britain stayed out of the war, and Hitler attacked Russia, the war in the east might have lasted longer. It might even have ended in a stalemate.
Russia would not have occupied Europe. Naziism would have collapsed after Hitler, much as Falangism collapsed after Franco. Communism might have collapsed before 1991.
Third World colonialism would still have ended, perhaps a bit later and not so violently. Nor might there be a flood of Third World immigrants into Europe.
Nobody would be speaking German outside Germany, much like nobody spoke Russian outside Russia despite Soviet occupation.
The mental gymnastics you go through to support killing Jews is amazing.
You do remember how climbing in bed with crazy man ended for Stalin?
But sure. Hitler just wanted to be "friends".
I think you are right: Rees-Mogg is just repeating the tired old cliché of „we would be speaking German“. (Sir Jacob, who is a man of erudition, really ought to refrain from using cheap slogans better suited to an alehouse than to a serious debate).
There is absolutely no proof that the Nazis would have foisted the German language upon the British. The regimes allied with Hitler had, of course, diplomats and interpreters who spoke German as go-betweens - but definitely not the ordinary people.
However, the problem with Hitler was that he had broken his promise to the Czechs, British and French that he would be content with Austria and the Sudetenland, as would have been arguable on the grounds of the right of self-determination - though, in practice, that would have fitted Germanophone Austria better than the Lands of the Bohemian Crown, which had been inhabited by two peoples since the High Middle Ages (or, as some have argued, one people which happens to speak two different languages).
Another matter was the annexation/return of the Memelland the same month of March 1939 (though there had been no plebiscite after 1919 either, just as there hadn’t been one in the Sudetenland, in South Tyrol et al.).
The eyes of the world were watching, however, after March 1939…and London, Paris and Warsaw had grown suspicious. With due reason. 😔
Still, had Hitler died early in 1939, he might have been regarded today as Mao is in China: 70% good, 30% bad, or thereabouts.
Still, we can simply not know what would have happened (I, for instance, would certainly have been euthanized as „unworthy of life“, due to my handicap).
Take Christianity: Nazism was decidedly anti-Christianity, until the war came and comfort was needed for those who mourned. In the USSR, the situation of the Orthodox Churches during 1941-45 improved vastly, but after the victory, religious expression was suppressed once more.
We can never know for sure: history is, after all, a chaotic system - not all of it, but to a large extent.