Yes. Whilst less typical to see on a UK transaction than a US transaction as an exit does not normally trigger the leaver provisions, there are two common types of acceleration that may be referenced:
VCs do not like single-trigger acceleration provisions for founder shares that are linked to termination of a founder's employment. They argue that equity in a start-up should be earned, and if a founder is terminated, then the founder’s shares should not continue to vest. Sometimes founders can negotiate having a portion of their shares accelerate (usually 6-12 months’ worth of vesting) if they are involuntarily terminated, or leave the company for good reason (i.e., they are demoted, or the company’s headquarters are moved). However, under most agreements, there is no acceleration if the founder voluntarily quits or is terminated for "cause".
VCs similarly do not like single-trigger acceleration on the sale of the company. They argue that it reduces the value of the company to a buyer. Buyers typically want to retain founders, and if the founders are already fully vested, it will be harder for them to do that. If founders and VCs agree upon single-trigger acceleration in these cases, it is often limited to a portion of the founders’ unvested shares.