Read point 8 in your link - the 100,000 net target was from the previous (2015 and 2017) manifestos, but was never taken seriously and was ditched in favour of the looser points-based system in 2019.
Both the Tories and Labour shifted their position several times in the 2010s, but few people based their votes on it. The only real change in policy came with the Brexit referendum, which was widely interpreted as being a desire for a shift from European to Commonwealth immigration.
The recent wave of concern is a new thing, and it remains to be seen whether it will continue now that the Brexit migration surge has tailed off or whether the online shit-stirring will be enough to sustain it for longer.
Both the Tories and Labour shifted their position several times in the 2010s, but few people based their votes on it. The only real change in policy came with the Brexit referendum, which was widely interpreted as being a desire for a shift from European to Commonwealth immigration.
The recent wave of concern is a new thing, and it remains to be seen whether it will continue now that the Brexit migration surge has tailed off or whether the online shit-stirring will be enough to sustain it for longer.