A short excerpt from the supertest patch notes for 9.14:
Simplified vehicle module research for beginners
To simplify the process of familiarising new players to the game, the research system for Tiers I and II has been changed. Tier I Vehicles will have just one module available for research - a gun. Tier II vehicles will get the opportunity to research one module of each type (engine, gun, suspension, radio, turret).
Last post covered tier 1s. This post covers tier 2s.
ALL NON-PREMIUM TANKS - Reduced to a single radio with no upgradable module available.
ALL PREMIUM TANKS - No change.
Type 89 I-Go/Chi-Ro - Reduced to a radio of 300m signal range, down from 425m.
Cruiser III - Reduced to stock radio, down to 350m signal range from 450m.
Cruiser I - Reduced to a radio of 350m signal range, down from 375m.
Pz. II - Given a different radio from any it had before, down to 310m signal range from 455m.
VAE Type B - Loses its weakest gun, the stock 37mm KwK 36. New stock gun is the medium-high alpha 47mm Vickers QF. No top end changes (signal range is still 300m).
M2 LT - Signal range completely gutted from being left to stock radio, down to 265m signal range from 615m.
Pz. 35t - Loses the weaker autocannon. Reduced to single stock radio, down to 290m signal range from 550m.
T2 MT - Signal range completely gutted from being left to stock radio, down to 265m signal range from 615m (now I have to retrain my commander to drop Relaying, RIP).
H35 - Reduced to stock radio, down to 300m signal range from 360m.
BT-2 - Loses three guns - the 37mm Hotchkiss (stock gun), the 23mm VJa (better of the two autocannons), and the 37mm ZiS-19 (top gun). Stock 37mm B-3 is a good improvement, but 45mm 20K top is much worse than ZiS-19. Keeps 300m signal range radio.
T-26 - Loses the autocannon. Keeps the 37mm ZiS-19 as top gun and 300m signal range radio.
D1 - Stock gun removed, spot taken by the autocannon. Reduced to stock radio, down to 300m signal range from 360m.
M2A4 - Reduced to a radio of 350m signal range, down from 375m.
R35 - No change.
20mm TNSh removed (arguably best autocannon for the tank). Keeps 300m signal range radio.
Pz. I - Given a different radio from any it had before, down to 310m signal range from 455m.
Type 95 Ha-Go - Reduced to a radio of 350m signal range, down from 425m.
FCM 36 - Reduced to a radio of 290m signal range, down from 300m.
Chi-Ni - Reduced to a radio of 350m signal range, down from 425m.
T3 HMC - No change.
LT vz. 35t - No change.
Vickers Mk. II - Stock gun removed, spot taken by the 6-pdr Mk II. Reduced to a radio of 250m signal range, down from 375m.
PzJg I - Signal range completely gutted from being left to stock radio, down to 265m signal range from 700m.
UC 2-pdr - Reduced to a radio of 350m signal range, down from 375m.
AT-1 - Loses its most accurate 37mm ZiS-19S. Keeps 300m signal range radio.
Renault FT AC - Stock gun removed, spot taken by the slightly more accurate model. Keeps 300m signal range radio.
Clearly, the biggest change here is to signal range. If the meme is true that pubs don't watch the minimap, then this change has little negative impact. I watch the minimap though, and the impact of this is considerable, at least on some tanks. You don't meed much more than 200m signal range on a map like Mittentard to stay in touch with your teammates (except for arty). 300 to 350 meters is sufficient for Mines, but only if you're in the middle, and a similar sentiment can be echoed for Himmelsdorf. Ruinberg is probably where this will have the greatest impact, putting city players out of touch with hill players, which could lead to a blinding effect that would make it very hard to see targets or enemies hitting you at >400m along the main east-west road.
Notable losers in this department are the American tanks, T2 and M2. Both of them currently have a meta play style that puts them on the front lines anyways, but if WG should ever switch things up again back to a vision meta, these tanks will be far less relevant for lacking their amazing tool for keeping in touch with allied campers everywhere. I remember grinding my 5.6k XP for my T2's radio and how delighted I was to basically never be out of signal range of any of my allies. So much for that now. Even with the worst range in the tier, I don't think it's bad enough to make a big difference on how good the M2 is, nor is it enough reason to start playing the British version instead. The Pz. 35t and PzJg I were also downgraded significantly, but nobody plays them anyways, so whatever. In other news, the Tetrarch still has 525m of signal range and is still an awful tank.
The only considerable firepower changes are to the BT-2, AT-1,
and perhaps the T-60, but this really isn't important. The AT-1 can't really get any worse anyways, the BT-2's best gun didn't fit in the current meta that much , and the T-60's lost gun wasn't even that great.