A big part of the US peace deal with the Taliban was for the group to sever all ties with al-Qaeda. They insisted they did so, but the US military keeps accusing them of secretly keeping ties.
Signs are that a lot of those ties are lower level, and in trying to avoid that perception, the Taliban has issued a new statement to its members telling them they must avoid giving shelter to foreign fighters, and absolutely not allow foreigners to join them.
The idea is to not just avoid ties in practice, but to avoid the perception of ties. Since this was a big part of the peace deal, the Taliban is looking to honor that, at a time when the big part on the US side, the pullout, remains in doubt.
If the US keeps going and doesn’t honor the peace, this will be good PR for the Taliban internationally, and even if the US continues to make allegations of al-Qaeda ties, those claims aren’t looking very true anymore, and may look like an excuse, which they of course are.