Nearly 55% of voters in Switzerland on Sunday rejected an initiative championed by the top right-wing party to cap the rich Alpine country’s population at 10 million, early results showed.
The populist Swiss People’s Party, which has the most seats in parliament, has stirred up and fostered anti-migration sentiment over the years, notably about an influx of workers from the neighboring European Union.
Some have dubbed the proposal a “Swiss Brexit” because it could jeopardize Switzerland’s deep ties to the European Union anchored by deals that foster economic growth, cultural ties and cross-border travel, among other things. Switzerland is not one of the EU’s 27 member states, but it is all but surrounded by four of them


Depends entirely on how the voting results are coming in. It’s entirely reasonable to call a result if the sample of votes counted already is a representative sample of the whole.
A counter example would be the recent elections in California. The early results came in from rural red areas for the governors race. So the early results were heavily weighed to the voting trends of those counties rather than the much different high density urban counties.
Also. Article mentions 55% of voters. It never said 55% of the total population. It just also stated independently a 59% total turnout. They wrote it perfectly fine.
Actual results map for anyone interested.
https://abstimmungen.admin.ch/en/details?proposalId=6860
TLDR: There is nothing wrong with the way the article shared percentages or inferring results from a partial count.