God told Moses of these appointments in Ex. 31:1-11 and detailed the tasks that Bezaleel and Aholiab were to accomplish. God filled them both with the Spirit at that time, not before, but when God told Moses of their appointed work.
NKJV Exodus 31:1-11,
"Then the Lord spoke to Moses, saying: 2 “See, I have called by name Bezalel the son of Uri, the son of Hur, of the tribe of Judah. 3 And I have filled him with the Spirit of God, in wisdom, in understanding, in knowledge, and in all manner of workmanship, 4 to design artistic works, to work in gold, in silver, in bronze, 5 in cutting jewels for setting, in carving wood, and to work in all manner of workmanship.
6 “And I, indeed I, have appointed with him Aholiab the son of Ahisamach, of the tribe of Dan; and I have put wisdom in the hearts of all the gifted artisans, that they may make all that I have commanded you: 7 the tabernacle of meeting, the ark of the Testimony and the mercy seat that is on it, and all the furniture of the tabernacle— 8 the table and its utensils, the pure gold lampstand with all its utensils, the altar of incense, 9 the altar of burnt offering with all its utensils, and the laver and its base— 10 the garments of ministry,[a] the holy garments for Aaron the priest and the garments of his sons, to minister as priests, 11 and the anointing oil and sweet incense for the holy place. According to all that I have commanded you they shall do.”
God delegated the tasks and skills to Bezaleel and then to Aholiab, and they were to teach others the skills necessary to build the tabernacle. The verbs are the present perfect tenses of "hath (have) filled" and "hath (have) called".
Young's Literal Translation, Ex. 35:30-35:
"And Moses saith unto the sons of Israel, `See, Jehovah hath called by name Bezaleel, son of Uri, son of Hur, of the tribe of Judah,
31 and He doth fill him [with] the Spirit of God, in wisdom, in understanding, and in knowledge, and in all work,
32 even to devise devices to work in gold, and in silver, and in brass,
33 and in graving of stones for settings, and in graving of wood to work in any work of design.
34 `And to direct He hath put in his heart, he and Aholiab, son of Ahisamach, of the tribe of Dan;
35 He hath filled them with wisdom of heart to do every work, of engraver, and designer, and embroiderer (in blue, and in purple, in scarlet, and in linen), and weaver, who do any work, and of designers of designs."
Compare the action of the verbs from YLT to the NKJV:
"30 And Moses said to the children of Israel, “See, the Lord has called by name Bezalel the son of Uri, the son of Hur, of the tribe of Judah; 31 and He has filled him with the Spirit of God, in wisdom and understanding, in knowledge and all manner of workmanship, 32 to design artistic works, to work in gold and silver and bronze, 33 in cutting jewels for setting, in carving wood, and to work in all manner of artistic workmanship.
34 “And He has put in his heart the ability to teach, in him and Aholiab the son of Ahisamach, of the tribe of Dan. 35 He has filled them with skill to do all manner of work of the engraver and the designer and the tapestry maker, in blue, purple, and scarlet thread, and fine linen, and of the weaver—those who do every work and those who design artistic works."
God chose the ones from the congregation whom He knew were best suited for the purpose. They may have had some skills or knowledge of these skills, or were at the very least the most capable of learning them. But, they were God's choice for accomplishing the work. They were filled with the Spirit at that time, and not earlier in life.
Both Bezaleel and Aholiab were filled with the Spirit in order to accomplish the work of building the tabernacle when Moses called them together. God delegated to them both to teach others the skills needed to do the work. In that way many could quickly learn how to build it.
As all of the people had contributed of their gold and silver, as well as other materials to build the tabernacle, these appointments by God assured the people that the work would be accomplished with the necessary skills without wasting or spoiling the materials.
Jamieson-Faussett-Brown Commentary :
"See, the Lord hath called by name Bezaleel, the son of Uri, &c.—Moses had made this communication before [see Ex 31:2-5; also see on Ex 31:2]. But now that the collection had been made, the materials were contributed, and the operations of building about to be commenced, it was with the greatest propriety he reminded the people that the individuals entrusted with the application of their gold and silver had been nominated to the work by authority to which all would bow." Source: Biblehub