Malolactic conversion will typically reduce acidity. Malic acid, a
dicarboxylic acid, gets decarboxylated to form lactic acid, a
monocarboxylic acid, and CO2(g). This will likely raise the pH
(though not dramically in my hands), not lower it.

Malate, like residual sugar, is a potential energy source for
bacteria. One goal of ML'ing is to remove that potential energy
source. Many species of lactic acid bacteria may be present in a
wine. Some are benign, some are considered spoilage bacteria. Any of
them may eventually utilize the malate under the right conditions
(temp above 65F, pH above 3.2, low sulfite levels, sufficient
nutrients, etc.). It can and does occur after bottling, which can be
heartbreaking after all your effort, leaving you with spoiled wine.
Encouraging the ML conversion by innoculating with a benign strain (O.
oenos) helps me sleep a bit better at night.

To ML or not is entirely up to you. Be sure to maintain adequate SO2
levels for your wine's pH if you choose not to ML.

RD