There may be several reasons for the browning such as winter damage, past fungal disease, possible scale, a sucking insect, etc. You may have to do some detective work.
In general, cherry laurels grow best in a well drained soil in morning sun and afternoon shade. Has something changed in the area such as drainage, downspouts? They will not be happy in a poorly drained soil and susceptible to roots rots. Check the drainage in the area. Make sure mulch is no thicker than several inches and keep away from the base of the shrubs. Thick mulch is attractive to boring insects. Water the plants during dry periods during the growing season.
Many broadleaved evergreens such as cherry laurel, camellia have been subject to winter damage this season. See our website for more information https://extension.umd.edu/hgic/winter-damage-trees-and-shrubs
At this point, the old foliage on the cherry laurel should drop off. Simply rake up. Once new growth starts should be okay.
The holes in the cherry laurel looks like a shot hole fungus. The shot hole symptoms on leaves (in your photo) occur when the centers of the spots fall out. It does cause cosmetic damage but is not very serious. The best management practices for most leaf spotting diseases involve pruning and removal of infected leaves and dead twigs during the winter or dry summer months. Mature shrubs can be thinned for better air circulation. Rake and remove infected fallen leaves in the fall. In the summer, avoid overhead irrigation.
Cherry laurels are also prone to scale insects such as the white prunicola scale. This is a sucking insect that can cause dieback. Monitor for these scale insects - look along the branches and stems for small disc or oystershell shapes that can be scraped off. See our website http://extension.umd.edu/learn/armored-and-soft-scales-trees-and-shrubs