Does the UA revised ranger's companion keep its skill bonuses?

Question

In the September 2016 Unearthed Arcana The Ranger, Revised, it says:

Your companion uses your proficiency bonus rather than its own.

The ape, for example, has a +5 bonus to Athletics and +3 to Perception. When the ape becomes a ranger's companion, does the ranger's proficiency bonus compound with these bonuses or replace them? That is, are these bonuses considered the ape's "proficiency bonus"?

It also says:

Your animal companion gains proficiency in two skills of your choice.

Is the ape considered already proficient with Athletics and Perception?

Answer 1

The Ape is proficient with both of those skills. From the D&D5e SRD:

The Skills entry is reserved for monsters that are proficient in one or more skills.

That same document has a Proficiency Bonus by Challenge Rating table that says that a CR 1/2 creature, like the Ape, has a proficiency bonus of +2. We can then take the stat bonuses from the 16 Str (+3) and 12 Wis (+1) to get the Ape's total modifiers to those skills.

So to determine what the Ape Companion's actual modifiers are for those skills you would take the stat bonus (+3 and +1) and add the ranger's proficiency bonus. You would do the same thing for the other skills you choose for it to learn.