Not really my usual territory but this caught my eye because I noticed something similar near Rendlesham back in October. Three towers that definitely weren't there the week before, all within about a mile of each other. Asked a mate who works in telecoms and he just said "upgrade rollout" which felt like the most nothing answer ever.
What gets me is the timing. Not the towers themselves, I get that infrastructure gets updated, but the specific window before that storm system came through was odd. Two days before, they're up. Storm hits. Then the signal in my area was actually worse than before they appeared.
Probably nothing, but I've been doing this long enough to know that "probably nothing" is worth at least asking about. Anyone actually managed to find planning permission records for new tower installations in their area? That should be publicly accessible and would at least rule out the mundane explanation.