It is context dependent.
In principle, no doors open or close - since the latest round of GCSE revisions, the content of double is plenty to provide a good basis for A level (for Physics, for example, there is a single topic, in Y13, where there is a gap).
Anecdotally, DD and some friends moved from a double-only school to a high performing triple-only school, had no issues in any sciences, and got the grades they needed for medicine, Oxbridge etc.
However, if your child is in a school where double and triple are offered, and the more able typically choose triple, then despite the above, the pitch and pace of double may be aimed at securing 4s, 5s and 6s, while triple lessons will be pitched at those with predictions of 7/8/9. In that case, very able students may be locally disadvantaged by taking double.