While the war is ongoing with France and the UK, those would be pretty empty gains for the Central Powers, given that the Entente would (maybe not-so) simply occupy them.
Of more immediate value might be the use of Italian road, rail, and basing infrastructure in order to open a second front with France across the Italian frontier. If this occurs, I'm not so sure the Entente would treat Italy as a truly neutral power, to say nothing of what most Italians might think of such an agreement.
That being said, Switzerland would be directly between the northern and southern French fronts, with significant potential value in allowing the transit of German/Austrian troops, supplies, or various material. Post-Bismark Imperial Germany historically displayed diplomacy so ham-handed it would shame pigs everywhere, so there's lots of potential for negotiations with the Swiss to break down.
If the Central Powers and Switzerland are dropping into a dangerously hostile level of relations in the desperate last phases of the war, making one last great gamble might seem worthwhile to Berlin...