Ensembl and UCSC Genome Browser both import their variant data from dbSNP. When new 1000 Genomes variants have been released it can take some time for them to be accessioned by dbSNP and make their way to the browsers.
When this happens we try to ensure there is a version of our own browser which displays the data in the meantime. Both Ensembl and UCSC support attaching VCF files to them for visualisation