Thanks for reaching out with your question and for providing pictures. From your photos, it does look like there is new growth beginning to sprout from lower on the stem. As the temperature begins to warm up, you'll most likely see your plants start to bush out a little bit more. One thing you could try is slightly less aggressive pruning by pinching off the tops of the stems to encourage more side growth rather than vertical growth. 

In the future if you do want to prune shorter, one thing to keep in mind is that you don't want to cut stems lower than where the leaves on the plant start. It's best to do this in the fall or in the very early spring.

Assuming that the leaves when you first planted the sage were much larger, there are a few things you could consider to promote better leaf growth: 

* Make sure that you water when the soil is dry to the touch (sage is drought tolerant, so be careful not to over water)

* Ensure that your plants get enough sunlight. This can also help with reducing the legginess of plants. 

* Make sure that you maintain good air circulation around the plants to reduce chances of powdery mildew

*Make sure you have enough space for your plants to grow. It's hard to tell from your pictures how large of a pot the plants are in, but if it's smaller than 12" in diameter, you may want to consider going up about an inch in diameter.

Given the age of the plants, it may also be worth considering replacing the plants after this season. It's not uncommon to need to replace sage plants every 3-4 years. You can find more guidance here: https://extension.umd.edu/resource/sage.

Happy gardening!